Tony Pearson is a Master Inventor and Senior IT Architect for the IBM Storage product line at the
IBM Systems Client Experience Center in Tucson Arizona, and featured contributor
to IBM's developerWorks. In 2016, Tony celebrates his 30th year anniversary with IBM Storage. He is
author of the Inside System Storage series of books. This blog is for the open exchange of ideas relating to storage and storage networking hardware, software and services.
(Short URL for this blog: ibm.co/Pearson )
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This week, July 26-30, 2010, I am in Washington DC for the annual [2010 System Storage Technical University]. As with last year, we have joined forces with the System x team. Since we are in Washington DC this time, IBM added a "Federal Track" to focus on government challenges and solutions. So, basically, offering attendees the option to attend three conferences for one low price.
This conference was previously called the "Symposium", but IBM changed the name to "Technical University" to emphasize the technical nature of the conference. No marketing puffery like "Journey to the Private Cloud" here! Instead, this is bona fide technical training, qualifying attendees to count this towards their Continuing Professional Education (CPE).
(Note to my readers:The blogosphere is like a playground. In the center are four-year-olds throwing sand into each other's faces, while mature adults sit on benches watching the action, and only jumping in as needed. For example, fellow blogger Chuck Hollis (EMC) got sand in his face for promising to resign if EMC ever offered a tacky storage guarantee, and then [failed to follow through on his promise] when it happened.
Several of my readers asked me to respond to another EMC blogger's latest [fistful of sand].
A few months ago, fellow blogger Barry Burke (EMC) committed to [stick to facts] in posts on his Storage Anarchist blog. That didn't last long! BarryB apparently has fallen in line with EMC's over-promise-then-under-deliver approach. Unfortunately, I will be busy covering the conference and IBM's robust portfolio of offerings, so won't have time to address BarryB's stinking pile of rumor and hearsay until next week or later. I am sorry to disappoint.)
This conference is designed to help IT professionals make their business and IT infrastructure more dynamic and, in the process, help reduce costs, mitigate risks, and improve service. This technical conference event is geared to IT and Business Managers, Data Center Managers, Project Managers, System Programmers, Server and Storage Administrators, Database Administrators, Business Continuity and Capacity Planners, IBM Business Partners and other IT Professionals. This week will offer over 300 different sessions and hands-on labs, certification exams, and a Solutions Center.
For those who want a quick stroll through memory lane, here are my posts from past events:
In keeping up with IBM's leadership in Social Media, IBM Systems Lab Services and Training team running this event have their own [Facebook Fan Page] and
[blog]. IBM Technical University has a Twitter account [@ibmtechconfs], and hashtag #ibmtechu. You can also follow me on Twitter [@az990tony].
Well, I'm back safely from my tour of Asia. I am glad to report that Tokyo, Beijing and Kuala Lumpur are pretty much how I remember them from the last time I was there in each city. I have since been fighting jet lag by watching the last thirteen episodes of LOST season 6 and the series finale.
Recently, I have started seeing a lot of buzz on the term "Storage Federation". The concept is not new, but rather based on the work in database federation, first introduced in 1985 by [A federated architecture for information management] by Heimbigner and McLeod. For those not familiar with database federation, you can take several independent autonomous databases, and treat them as one big federated system. For example, this would allow you to issue a single query and get results across all the databases in the federated system. The advantage is that it is often easier to federate several disparate heterogeneous databases than to merge them into a single database. [IBM Infosphere Federation Server] is a market leader in this space, with the capability to federate DB2, Oracle and SQL Server databases.
Storage expansion: You want to increase the storage capacity of an existing storage system that cannot accommodate the total amount of capacity desired. Storage Federation allows you to add additional storage capacity by adding a whole new system.
Storage migration: You want to migrate from an aging storage system to a new one. Storage Federation allows the joining of the two systems and the evacuation from storage resources on the first onto the second and then the first system is removed.
Safe system upgrades: System upgrades can be problematic for a number of reasons. Storage Federation allows a system to be removed from the federation and be re-inserted again after the successful completion of the upgrade.
Load balancing: Similar to storage expansion, but on the performance axis, you might want to add additional storage systems to a Storage Federation in order to spread the workload across multiple systems.
Storage tiering: In a similar light, storage systems in a Storage Federation could have different capacity/performance ratios that you could use for tiering data. This is similar to the idea of dynamically re-striping data across the disk drives within a single storage system, such as with 3PAR's Dynamic Optimization software, but extends the concept to cross storage system boundaries.
To some extent, IBM SAN Volume Controller (SVC), XIV, Scale-Out NAS (SONAS), and Information Archive (IA) offer most, if not all, of these capabilities. EMC claims its VPLEX will be able to offer storage federation, but only with other VPLEX clusters, which brings up a good question. What about heterogenous storage federation? Before anyone accuses me of throwing stones at glass houses, let's take a look at each IBM solution:
IBM SAN Volume Controller
The IBM SAN Volume Controller has been doing storage federation since 2003. Not only can IBM SAN Volume Controller bring together storage from a variety of heterogenous storage, the SVC cluster itself can be a mix of different hardware models. You can have a 2145-8A4 node pair, 2145-8G4 node pair, and the new 2145-CF8 node pair, all combined together into a single SVC cluster. Upgrading SVC hardware nodes in an SVC cluster is always non-disruptive.
IBM XIV storage system
The IBM XIV has two kinds of independent modules. Data modules have processor, cache and 12 disks. Interface modules are data modules with additional processor, FC and Ethernet (iSCSI) adapters. Because these two modules play different roles in an XIV "colony", that number of each type is predetermined. Entry-level six-module systems have 2 interface and 4 data modules. Full 15-module systems have 6 interface and 9 data modules. Individual modules can be added or removed non-disruptively in an XIV.
IBM Scale-Out NAS
The SONAS is comprised of three kinds of nodes that work together in concert. A management node, one or more interface nodes, and two or more storage nodes. The storage nodes are paired to manage up to 240 nodes in a storage pod. Individual interface or data nodes can be added or removed non-disruptively in the SONAS. The underlying technology, the General Parallel File System, has been doing storage federation since 1996 for some of the largest top 500 supercomputers in the world.
IBM Information Archive (IA)
For the IA, there are 1, 2 or 3 nodes, which manages a set of collections. A collection can either be file-based using industry-standard NAS protocols, or object-based using the popular System Storage™ Archive Manager (SSAM) interface. Normally, you have as many collections as you have nodes, but nodes are powerful enough to manage two collections to provide N-1 availability. This allows a node to be removed, and a new node added into the IA "colony", in a non-disruptive manner.
Even in an ant colony, there are only a few types of ants, with typically one queen, several males, and lots of workers. But all the ants are red. You don't see colonies that mix between different species of ants. For databases, federation was a way to avoid the much harder task of merging databases from different platforms. For storage, I am surprised people have latched on to the term "federation", given our mixed results in the other "federations" we have formed, which I have conveniently (IMHO) ranked from least effective to most effective:
The Union of Soviet Socialist Republics (USSR)
My father used to say, "If the Soviet Union were in charge of the Sahara desert, they would run out of sand in 50 years." The [Soviet Union] actually lasted 68 years, from 1922 to 1991.
The United Nations (UN)
After the previous League of Nations failed, the UN was formed in 1945 to facilitate cooperation in international law, international security, economic development, social progress, human rights, and the achieving of world peace by stopping wars between countries, and to provide a platform for dialogue.
The European Union (EU)
With the collapse of the Greek economy, and the [rapid growth of debt] in the UK, Spain and France, there are concerns that the EU might not last past 2020.
The United States of America (USA)
My own country is a federation of states, each with its own government. California's financial crisis was compared to the one in Greece. My own state of Arizona is under boycott from other states because of its recent [immigration law]. However, I think the US has managed better than the EU because it has evolved over the past 200 years.
The Organization of the Petroleum Exporting Countries [OPEC]
Technically, OPEC is not a federation of cooperating countries, but rather a cartel of competing countries that have agreed on total industry output of oil to increase individual members' profits. Note that it was a non-OPEC company, BP, that could not "control their output" in what has now become the worst oil spill in US history. OPEC was formed in 1960, and is expected to collapse sometime around 2030 when the world's oil reserves run out. Matt Savinar has a nice article on [Life After the Oil Crash].
United Federation of Planets
The [Federation] fictitiously described in the Star Trek series appears to work well, an optimistic view of what federations could become if you let them evolve long enough.
Given the mixed results with "federation", I think I will avoid using the term for storage, and stick to the original term "scale-out architecture".
Here I am, day 11 of a 17-day business trip, on my last leg of the trip this week, in Kuala Lumpur in Malaysia. I have been flooded with requests to give my take on EMC's latest re-interpretation of storage virtualization, VPLEX.
I'll leave it to my fellow IBM master inventor Barry Whyte to cover the detailed technical side-by-side comparison. Instead, I will focus on the business side of things, using Simon Sinek's Why-How-What sequence. Here is a [TED video] from Garr Reynold's post
[The importance of starting from Why].
Let's start with the problem we are trying to solve.
Problem: migration from old gear to new gear, old technology to new technology, from one vendor to another vendor, is disruptive, time-consuming and painful.
Given that IT storage is typically replaced every 3-5 years, then pretty much every company with an internal IT department has this problem, the exception being those companies that don't last that long, and those that use public cloud solutions. IT storage can be expensive, so companies would like their new purchases to be fully utilized on day 1, and be completely empty on day 1500 when the lease expires. I have spoken to clients who have spent 6-9 months planning for the replacement or removal of a storage array.
A solution to make the data migration non-disruptive would benefit the clients (make it easier for their IT staff to keep their data center modern and current) as well as the vendors (reduce the obstacle of selling and deploying new features and functions). Storage virtualization can be employed to help solve this problem. I define virtualization as "technology that makes one set of resources look and feel like a different set of resources, preferably with more desirable characteristics.". By making different storage resources, old and new, look and feel like a single type of resource, migration can be performed without disrupting applications.
Before VPLEX, here is a breakdown of each solution:
Non-disruptive tech refresh, and a unified platform to provide management and functionality across heterogeneous storage.
Non-disruptive tech refresh, and a unified platform to provide management and functionality between internal tier-1 HDS storage, and external tier-2 heterogeneous storage.
Non-disruptive tech refresh, with unified multi-pathing driver that allows host attachment of heterogeneous storage.
New in-band storage virtualization device
Add in-band storage virtualization to existing storage array
New out-of-band storage virtualization device with new "smart" SAN switches
SAN Volume Controller
HDS USP-V and USP-VM
For IBM, the motivation was clear: Protect customers existing investment in older storage arrays and introduce new IBM storage with a solution that allows both to be managed with a single set of interfaces and provide a common set of functionality, improving capacity utilization and availability. IBM SAN Volume Controller eliminated vendor lock-in, providing clients choice in multi-pathing driver, and allowing any-to-any migration and copy services. For example, IBM SVC can be used to help migrate data from an old HDS USP-V to a new HDS USP-V.
With EMC, however, the motivation appeared to protect software revenues from their PowerPath multi-pathing driver, TimeFinder and SRDF copy services. Back in 2005, when EMC Invista was first announced, these three software represented 60 percent of EMC's bottom-line profit. (Ok, I made that last part up, but you get my point! EMC charges a lot for these.)
Back in 2006, fellow blogger Chuck Hollis (EMC) suggested that SVC was just a [bump in the wire] which could not possibly improve performance of existing disk arrays. IBM showed clients that putting cache(SVC) in front of other cache(back end devices) does indeed improve performance, in the same way that multi-core processors successfully use L1/L2/L3 cache. Now, EMC is claiming their cache-based VPLEX improves performance of back-end disk. My how EMC's story has changed!
So now, EMC announces VPLEX, which sports a blend of SVC-like and Invista-like characteristics. Based on blogs, tweets and publicly available materials I found on EMC's website, I have been able to determine the following comparison table. (Of course, VPLEX is not yet generally available, so what is eventually delivered may differ.)
Scalable, 1 to 4 node-pairs
One size fits all, single pair of CPCs
SVC-like, 1 to 4 director-pairs
Works with any SAN switches or directors
Required special "smart" switches (vendor lock-in)
SVC-like, works with any SAN switches or directors
Broad selection of IBM Subsystem Device Driver (SDD) offered at no additional charge, as well as OS-native drivers Windows MPIO, AIX MPIO, Solaris MPxIO, HP-UX PV-Links, VMware MPP, Linux DM-MP, and comercial third-party driver Symantec DMP.
Limited selection, with focus on priced PowerPath driver
Invista-like, PowerPath and Windows MPIO
Read cache, and choice of fast-write or write-through cache, offering the ability to improve performance.
No cache, Split-Path architecture cracked open Fibre Channel packets in flight, delayed every IO by 20 nanoseconds, and redirected modified packets to the appropriate physical device.
SVC-like, Read and write-through cache, offering the ability to improve performance.
Space-Efficient Point-in-Time copies
SVC FlashCopy supports up to 256 space-efficient targets, copies of copies, read-only or writeable, and incremental persistent pairs.
Like Invista, No
Remote distance mirror
Choice of SVC Metro Mirror (synchronous up to 300km) and Global Mirror (asynchronous), or use the functionality of the back-end storage arrays
No native support, use functionality of back-end storage arrays, or purchase separate product called EMC RecoverPoint to cover this lack of functionality
Limited synchronous remote-distance mirror within VPLEX (up to 100km only), no native asynchronous support, use functionality of back-end storage arrays
Provides thin provisioning to devices that don't offer this natively
Like Invista, No
SVC Split-Cluster allows concurrent read/write access of data to be accessed from hosts at two different locations several miles apart
I don't think so
PLEX-Metro, similar in concept but implemented differently
Non-disruptive tech refresh
Can upgrade or replace storage arrays, SAN switches, and even the SVC nodes software AND hardware themselves, non-disruptively
Tech refresh for storage arrays, but not for Invista CPCs
Tech refresh of back end devices, and upgrade of VPLEX software, non-disruptively. Not clear if VPLEX engines themselves can be upgraded non-disruptively like the SVC.
Heterogeneous Storage Support
Broad support of over 140 different storage models from all major vendors, including all CLARiiON, Symmetrix and VMAX from EMC, and storage from many smaller startups you may not have heard of
Invista-like. VPLEX claims to support a variety of arrays from a variety of vendors, but as far as I can find, only DS8000 supported from the list of IBM devices. Fellow blogger Barry Burke (EMC) suggests [putting SVC between VPLEX and third party storage devices] to get the heterogeneous coverage most companies demand.
Back-end storage requirement
Must define quorum disks on any IBM or non-IBM back end storage array. SVC can run entirely on non-IBM storage arrays
HP SVSP-like, requires at least one EMC storage array to hold metadata
SVC 2145-CF8 model supports up to four solid-state drives (SSD) per node that can treated as managed disk to store end-user data
Invista-like. VPLEX has an internal 30GB SSD, but this is used only for operating system and logs, not for end-user data.
In-band virtualization solutions from IBM and HDS dominate the market. Being able to migrate data from old devices to new ones non-disruptively turned out to be only the [tip of the iceberg] of benefits from storage virtualization. In today's highly virtualized server environment, being able to non-disruptively migrate data comes in handy all the time. SVC is one of the best storage solutions for VMware, Hyper-V, XEN and PowerVM environments. EMC watched and learned in the shadows, taking notes of what people like about the SVC, and decided to follow IBM's time-tested leadership to provide a similar offering.
EMC re-invented the wheel, and it is round. On a scale from Invista (zero) to SVC (ten), I give EMC's new VPLEX a six.
It seems everyone is talking about stacks, appliances and clouds.
On StorageBod, fellow blogger Martin Glassborow has a post titled [Pancakes!] He feels that everyone from Hitachi to Oracle is turning into the IT equivalent of the International House of Pancakes [IHOP] offering integrated stacks of software, servers and storage.
Cisco introduced its "Unified Computing System" about a year ago, [reinventing the datacenter with an all-Ethernet approach]. Cisco does not offer its own hypervisor software nor storage, so there are two choices. First, Cisco has entered a joint venture, called Acadia, with VMware and EMC, to form the Virtual Computing Environment (VCE) coalition. The resulting stack was named Vblock, which one blogger had hyphenated as Vb-lock to raise awareness to the proprietary vendor lock-in nature of this stack. Second, Cisco, VMware and NetApp had a similar set of [Barney press releases] to announce a viable storage alternative to those not married to EMC.
"Only when it makes sense. Oracle/Sun has the better argument: when you know exactly what you want from your database, we’ll sell you an integrated appliance that will do exactly that. And it’s fine if you roll your own.
But those are industry-wide issues. There are UCS/VCE specific issue as well:
Cost. All the integration work among 3 different companies costs money. They aren’t replacing existing costs – they are adding costs. Without, in theory, charging more.
Lock-in. UCS/Vblock is, effectively, a mainframe with a network backplane.
Barriers to entry. Are there any? Cisco flagged hypervisor bypass and large memory support as unique value-add – and neither seems any more than a medium-term advantage.
BOT? Build, Operate, Transfer. In theory Vblocks are easier and faster to install and manage. But customers are asking that Acadia BOT their new Vblocks. The customer benefit over current integrator practice? Lower BOT costs? Or?
Price. The 3 most expensive IT vendors banding together?
Longevity. Industry “partnerships” don’t have a good record of long-term success. Each of these companies has its own competitive stresses and financial imperatives, and while the stars may be aligned today, where will they be in 3 years? Unless Cisco is piloting an eventual takeover."
Fellow blogger Bob Sutor (IBM) has an excellent post titled
[Appliances and Linux]. Here is an excerpt:
"In your kitchen you have special appliances that, presumably, do individual things well. Your refrigerator keeps things cold, your oven makes them hot, and your blender purees and liquifies them. There is room in a kitchen for each of these. They work individually but when you are making a meal they each have a role to play in creating the whole.
You could go out and buy the metal, glass, wires, electrical gadgets, and so on that you would need to make each appliance but it is is faster, cheaper, and undoubtably safer to buy them already manufactured. For each device you have a choice of providers and you can pay more for additional features and quality.
In the IT world it is far more common to buy the bits and pieces that make up a final solution. That is, you might separately order the hardware components, the operating system, and the applications, and then have someone put them all together for you. If you have an existing configuration you might add more blades or more storage devices.
You don’t have to do this, however, in every situation. Just from a hardware perspective, you can buy a ready-made machine just waiting for the on switch to be flicked and the software installed. Conversely, you might get a pre-made software image with operating system and applications in place, ready to be provisioned to your choice of hardware. We can get even fancier in that the software image might be deployable onto a virtual machine and so be a ready made solution runnable on a cloud.
Thus in the IT world we can talk about hardware-only appliances, software-only appliances (often called virtual software appliances), and complete hardware and software combinations. The last is most comparable to that refrigerator or oven in your kitchen."
If your company was a restaurant, how many employees would you have on hand to produce your own electricity from gas generators, pump your own water from a well, and assemble your own toasters and blenders from wires and motors? I think this is why companies are re-thinking the way they do their own IT.
Rather than business-as-usual, perhaps a mix of pre-configured appliances, consisting of software, server and storage stacked to meet a specific workload, connected to public cloud utility companies, might be the better approach. By 2013, some analysts feel that as many as 20 percent of companies might not even have a traditional IT datacenter anymore.
“By employing techniques like virtualization, automated management, and utility-billing models, IT managers can evolve the internal datacenter into a ‘private cloud’ that offers many of the performance, scalability, and cost-saving benefits associated with public clouds. Microsoft provides the foundation for private clouds with infrastructure solutions to match a range of customer sizes, needs and geographies.
The public cloud:
“Cloud computing is expanding the traditional web-hosting model to a point where enterprises are able to off-load commodity applications to third-party service providers (hosters) and, in the near future, the Microsoft Azure Services Platform. Using Microsoft infrastructure software and Web-based applications, the public cloud allows companies to move applications between private and public clouds.”
Finally, I saw this from fellow blogger, Barry Burke(EMC), aka the Storage Anarchist, titled [a walk through the clouds] which is really a two-part post.
The first part describes a possible future for EMC customers written by EMC employee David Meiri, envisioning a wonderful world with "No more Metas, Hypers, BIN Files...."
The vision is a pleasant one, and not far from reality. While EMC prefers to use the term "private cloud" to refer to both on-premises and off-premises-but-only-your-employees-can-VPN-to-it-and-your-IT-staff-still-manages-it flavors, the overall vision is available today from a variety of Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS) and Software-as-a-Service (SaaS) providers.
A good analogy for "private cloud" might be a corporate "intranet" that is accessible only within the company's firewall. This allowed internal websites where information to be disseminated to employees could be posted, using standard HTML and standard web browsers that are already deployed on most PCs and workstations. Web pages running on an intranet can easily be moved to an external-facing website without too much rework or trouble.
The second part has Barry claiming that EMC has made progress towards a "Virtual Storage Server" that might be announced at next month's EMC World conference.
When people hear "Storage Virtualization" most immediately think of the two market leaders, IBM SAN Volume Controller and Hitachi Data Systems (HDS) Universal Storage Platform (USP) products. Those with a tape bent might throw in IBM's TS7000 virtual tape libraries or Oracle/Sun's Virtual Storage Manager (VSM). And those focused on software-only solutions might recall Symantec's Veritas Volume Manager (VxVM), DataCore's SANsymphony, or FalconStor's IPStor products.
But what about EMC's failed attempt at storage virtualization, the Invista? After five years of failing to deliver value, EMC has so far only publicised ONE customer reference account, and I estimate that perhaps only a few dozen actual customers are still running on this platform. Compare that to IBM selling tens of thousands of SAN Volume Controllers, and HDS selling thousands of their various USP-V and USP-VM products, and you quickly realize that EMC has a lot of catching up to do. EMC's first delivered Invista about 18 months after IBM SAN Volume Controller, similar to their introduction of Atmos being 18 months after our Scale-Out File Services (SoFS) and their latest CLARiiON-based V-Max coming out 18 months after IBM's XIV storage system.
So what will EMC's Invista follow-on "Virtual Storage Server" product look like? No idea. It might be another five years before you actually hear about a customer using it. But why wait for EMC to get their act together?
IBM offers solutions TODAY that can make life as easy as envisioned here. IBM offers integrated systems sold as ready-to-use appliances, customized "stacks" that can be built to handle particular workloads, residing on-premises or hosted at an IBM facility, and public cloud "as-a-service" offerings on the IBM Cloud.
They say "Great Minds think alike" and that imitation is "the sincerest form of flattery." Both of these quotes came to mind when I read fellow blogger Chuck Hollis' (EMC) excellent April 7th blog post [The 10 Big Ideas That Are Shaping IT Infrastructure Today]. Not surprisingly, some of his thoughts are similar to those I had presented two weeks ago in my March 22nd post [Cloud Computing for Accountants]. Here are two charts that caught my eye:
On page 13 of my deck, I had an old black and white photo of telephone operators, as part of a section on the history of selecting "cloud" as the iconic graphic to represent all networks. Chuck has this same graphic on his chart titled "#1 The Industrialization of IT Infrastructure".
Looks like Chuck and I use the same "stock photo" search facility!
On page 45 on my deck, I had a list of major "arms dealers" that deliver the hardware and software components needed to build Cloud Computing. Chuck has a similar chart, titled "#2 The Consolidation of the IT Industry", but with some interesting differences.
Let's look at some of the key differences:
The left-to-right order is slightly different. I chose a 1-2-4-2-1 symmetrical pattern purely on aesthetic reasons. My presentation was to a bunch of accountants, and so I was trying not to make it sound like an "Infomercial" for IBM products and offerings. My sequence is roughly chronological, in that Oracle announced its intention to acquire Sun, then Cisco, VMware and EMC announced their VCE coalition, followed closely by Cisco, VMware and NetApp announcing they work together well also, followed by [HP extended alliance with Microsoft] on Jan 13, 2010. As the IT marketplace is maturing, more and more customers are looking for an IBM-like one-stop shopping experience, and certainly various "mini-mall" alliances have formed to try to compete in this space.
I had HP and Microsoft in the same column, referring only to the above-mentioned January announcement. HP is all about private cloud hardware infrastructures, but Microsoft is all about "three screens and the public cloud", so not sure how well this alliance will work out from a Cloud Computing perspective. This was not to imply that the other stacks don't work well with Microsoft software. They all do. Perhaps to avoid that controversy, Chuck chose to highlight HP's acquisition of EDS services instead.
I used the vendor logos in their actual colors. Notice that the colors black, blue and red occur most often. These happen to be the three most popular ballpoint pen ink colors found on the very same paper documents these computer companies are trying to eliminate. Paper-less office, anyone? Chuck chose instead to colorize each stack with his own color scheme. While blue for IBM and orange for Sun Microsystems make some sense, it is not clear if he chose green for Cisco/VMware/EMC for any particular reason. Perhaps he was trying to subtly imply that the VCE stack is more energy efficient? Or maybe the green refers to money to indicate that the VCE stack is the most expensive? Either way, I would pit IBM's server/storage/software stack up against anything of comparable price from these other stacks in any energy efficiency bake-off.
What about the Cisco/VMware/NetApp combination? All three got together to assure customers this was a viable combination. IBM is the number one reseller of VMware, and VMware runs great with IBM's N series NAS storage, so I do not dispute Cisco's motivation here. It makes sense for Cisco to two-time EMC in this manner. Why should Cisco limit itself to a single storage supplier? Et tu VMware? Having VMware chose NetApp over its parent company EMC was a bit of a shock. No surprise that Chuck left NetApp out of his chart.
No love for Dell? I give Dell credit for their work with Virtual Desktop Images (VDI), and for embracing Ubuntu Linux for their servers. Dell's acquisitions of EqualLogic iSCSI-based disk systems and Perot Systems for services are also worth noting. Dell used to resell some of EMC's gear, but perhaps that relationship continues to fade away, as I [predicted back in 2007]. Chuck's decision to leave Dell off his chart speaks volumes to where this relationship stands, and where it is going.
Perhaps we are all in just one big ["echo chamber"], as we are all coming up with similar observations, talking to similar customers, and reviewing similar market analyst reports. I am glad, at least this time, that Chuck and I for the most part agree where the marketplace is going. We live in interesting times!
“In times of universal deceit, telling the truth will be a revolutionary act.”
-- George Orwell
Well, it has been over two years since I first covered IBM's acquisition of the XIV company. Amazingly, I still see a lot of misperceptions out in the blogosphere, especially those regarding double drive failures for the XIV storage system. Despite various attempts to [explain XIV resiliency] and to [dispel the rumors], there are still competitors making stuff up, putting fear, uncertainty and doubt into the minds of prospective XIV clients.
Clients love the IBM XIV storage system! In this economy, companies are not stupid. Before buying any enterprise-class disk system, they ask the tough questions, run evaluation tests, and all the other due diligence often referred to as "kicking the tires". Here is what some IBM clients have said about their XIV systems:
“3-5 minutes vs. 8-10 hours rebuild time...”
-- satisfied XIV client
“...we tested an entire module failure - all data is re-distributed in under 6 hours...only 3-5% performance degradation during rebuild...”
-- excited XIV client
“Not only did XIV meet our expectations, it greatly exceeded them...”
In this blog post, I hope to set the record straight. It is not my intent to embarrass anyone in particular, so instead will focus on a fact-based approach.
Fact: IBM has sold THOUSANDS of XIV systems
XIV is "proven" technology with thousands of XIV systems in company data centers. And by systems, I mean full disk systems with 6 to 15 modules in a single rack, twelve drives per module. That equates to hundreds of thousands of disk drives in production TODAY, comparable to the number of disk drives studied by [Google], and [Carnegie Mellon University] that I discussed in my blog post [Fleet Cars and Skin Cells].
Fact: To date, no customer has lost data as a result of a Double Drive Failure on XIV storage system
This has always been true, both when XIV was a stand-alone company and since the IBM acquisition two years ago. When examining the resilience of an array to any single or multiple component failures, it's important to understand the architecture and the design of the system and not assume all systems are alike. At it's core, XIV is a grid-based storage system. IBM XIV does not use traditional RAID-5 or RAID-10 method, but instead data is distributed across loosely connected data modules which act as independent building blocks. XIV divides each LUN into 1MB "chunks", and stores two copies of each chunk on separate drives in separate modules. We call this "RAID-X".
Spreading all the data across many drives is not unique to XIV. Many disk systems, including EMC CLARiiON-based V-Max, HP EVA, and Hitachi Data Systems (HDS) USP-V, allow customers to get XIV-like performance by spreading LUNs across multiple RAID ranks. This is known in the industry as "wide-striping". Some vendors use the terms "metavolumes" or "extent pools" to refer to their implementations of wide-striping. Clients have coined their own phrases, such as "stripes across stripes", "plaid stripes", or "RAID 500". It is highly unlikely that an XIV will experience a double drive failure that ultimately requires recovery of files or LUNs, and is substantially less vulnerable to data loss than an EVA, USP-V or V-Max configured in RAID-5. Fellow blogger Keith Stevenson (IBM) compared XIV's RAID-X design to other forms of RAID in his post [RAID in the 21st Centure].
Fact: IBM XIV is designed to minimize the likelihood and impact of a double drive failure
The independent failure of two drives is a rare occurrence. More data has been lost from hash collisions on EMC Centera than from double drive failures on XIV, and hash collisions are also very rare. While the published worst-case time to re-protect from a 1TB drive failure for a fully-configured XIV is 30 minutes, field experience shows XIV regaining full redundancy on average in 12 minutes. That is 40 times less likely than a typical 8-10 hour window for a RAID-5 configuration.
A lot of bad things can happen in those 8-10 hours of traditional RAID rebuild. Performance can be seriously degraded. Other components may be affected, as they share cache, connected to the same backplane or bus, or co-dependent in some other manner. An engineer supporting the customer onsite during a RAID-5 rebuild might pull the wrong drive, thereby causing a double drive failure they were hoping to avoid. Having IBM XIV rebuild in only a few minutes addresses this "human factor".
In his post [XIV drive management], fellow blogger Jim Kelly (IBM) covers a variety of reasons why storage admins feel double drive failures are more than just random chance. XIV avoids load stress normally associated with traditional RAID rebuild by evenly spreading out the workload across all drives. This is known in the industry as "wear-leveling". When the first drive fails, the recovery is spread across the remaining 179 drives, so that each drive only processes about 1 percent of the data. The [Ultrastar A7K1000] 1TB SATA disk drives that IBM uses from HGST have specified 1.2 million hours mean-time-between-failures [MTBF] would average about one drive failing every nine months in a 180-drive XIV system. However, field experience shows that an XIV system will experience, on average, one drive failure per 13 months, comparable to what companies experience with more robust Fibre Channel drives. That's innovative XIV wear-leveling at work!
Fact: In the highly unlikely event that a DDF were to occur, you will have full read/write access to nearly all of your data on the XIV, all but a few GB.
Even though it has NEVER happened in the field, some clients and prospects are curious what a double drive failure on an XIV would look like. First, a critical alert message would be sent to both the client and IBM, and a "union list" is generated, identifying all the chunks in common. The worst case on a 15-module XIV fully loaded with 79TB data is approximately 9000 chunks, or 9GB of data. The remaining 78.991 TB of unaffected data are fully accessible for read or write. Any I/O requests for the chunks in the "union list" will have no response yet, so there is no way for host applications to access outdated information or cause any corruption.
(One blogger compared losing data on the XIV to drilling a hole through the phone book. Mathematically, the drill bit would be only 1/16th of an inch, or 1.60 millimeters for you folks outside the USA. Enough to knock out perhaps one character from a name or phone number on each page. If you have ever seen an actor in the movies look up a phone number in a telephone booth then yank out a page from the phone book, the XIV equivalent would be cutting out 1/8th of a page from an 1100 page phone book. In both cases, all of the rest of the unaffected information is full accessible, and it is easy to identify which information is missing.)
If the second drive failed several minutes after the first drive, the process for full redundancy is already well under way. This means the union list is considerably shorter or completely empty, and substantially fewer chunks are impacted. Contrast this with RAID-5, where being 99 percent complete on the rebuild when the second drive fails is just as catastrophic as having both drives fail simultaneously.
Fact: After a DDF event, the files on these few GB can be identified for recovery.
Once IBM receives notification of a critical event, an IBM engineer immediately connects to the XIV using remote service support method. There is no need to send someone physically onsite, the repair actions can be done remotely. The IBM engineer has tools from HGST to recover, in most cases, all of the data.
Any "union" chunk that the HGST tools are unable to recover will be set to "media error" mode. The IBM engineer can provide the client a list of the XIV LUNs and LBAs that are on the "media error" list. From this list, the client can determine which hosts these LUNs are attached to, and run file scan utility to the file systems that these LUNs represent. Files that get a media error during this scan will be listed as needing recovery. A chunk could contain several small files, or the chunk could be just part of a large file. To minimize time, the scans and recoveries can all be prioritized and performed in parallel across host systems zoned to these LUNs.
As with any file or volume recovery, keep in mind that these might be part of a larger consistency group, and that your recovery procedures should make sense for the applications involved. In any case, you are probably going to be up-and-running in less time with XIV than recovery from a RAID-5 double failure would take, and certainly nowhere near "beyond repair" that other vendors might have you believe.
Fact: This does not mean you can eliminate all Disaster Recovery planning!
To put this in perspective, you are more likely to lose XIV data from an earthquake, hurricane, fire or flood than from a double drive failure. As with any unlikely disaster, it is best to have a disaster recovery plan than to hope it never happens. All disk systems that sit on a single datacenter floor are vulnerable to such disasters.
For mission-critical applications, IBM recommends using disk mirroring capability. IBM XIV storage system offers synchronous and asynchronous mirroring natively, both included at no additional charge.
The marketshare data for external disk systems has been released by IDC for 4Q09. Overall, the market dropped 0.7 percent, comparing 4Q09 versus 4Q08. While EMC was quick to remind everyone that they were able to [maintain their #1 position] in the storage subset of "external disk systems", with the same 23.7 percent marketshare they had back in 4Q08 and revenues that were essentially flat, the real story concerns the shifts in the marketplace for the other major players. IBM grew revenue 9 percent, putting it nearly 5 points of marketshare ahead of HP. HP revenues dropped 7 percent, moving it further behind. Not mentioned in the [IBM Press Release] were NetApp and Dell, neck and neck for fourth place, with NetApp gaining 16.8 percent in revenues, while Dell dropped 13.5 percent. Both NetApp and Dell now have about 8 percent marketshare each. These top five storage vendors represent nearly 70 percent of the marketshare.
Given that HP is IBM's number one competitor, not just in storage but all things IT, this was a major win. Bob Evans from InformationWeek interviews my fifth-line manager, IBM executive Rod Adkins [IBM Claims Hardware Supremacy] where he shares his views and opinions about HP, Oracle-Sun, Cisco and Dell.
I'll add my two cents on what's going on:
Shift in Servers causes Shift in Storage
Hundreds of customers are moving away from HP and Sun over to IBM servers, and with it, are chosing IBM's storage offerings as well. IBM's rock-solid strategy (which I outlined in my post [Foundations and Flavorings]) has helped explain the different products and how they are positioned. HP's use of Itanium processors, and Sun's aging SPARC line, are both reasons enough to switch to IBM's lastest POWER7 processors, running AIX, IBM i (formerly i5/OS) and Linux operating systems.
Thunder in the Clouds
Some analysts predict that by 2013, one out of five companies won't even have their own IT assets. IBM supports all flavors of private, public and hybrid cloud computing models. IBM has its own strong set of offerings, is also the number one reseller of VMware, and has cloud partnerships with both Google and Amazon. HP and Microsoft have recently formed an alliance, but they have different takes on cloud computing. HP wants to be the "infrastructure" company, but Microsoft wants to focus on its ["three screens and a public cloud"] strategy. Microsoft has decided not to make its Azure Cloud operating system available for private cloud deployments. By contrast, IBM can start you with a private cloud, then help you transition to a hybrid cloud, and finally to a public cloud.
In the latest eX5 announcement, IBM's x86-based servers can run 78 percent more virtual machines per VMware license dollar. This will give IBM an advantage as HP shifts from Itanium to an all x86-based server line.
Network Attached Storage
There seems to be a shift away from FC and iSCSI towards NAS and FCoE storage networking protocols. This bodes bad for HP's acquisition of LeftHand, and Dell's acquisition of EqualLogic. IBM's SONAS for large deployments, and N series for smaller deployments, will compete nicely against HP's StorageWorks X9000 system.
Storage on Paper no longer Eco-friendly
HP beats IBM when you include consumer products like printers, which some might consider "Storage on Paper". At IBM, we often joke that 96 percent of HP's profits come from over-priced ink cartridges. With the latest focus on the environment, people are printing less. I have been printing less myself, setting my default printer to generate a PDF file instead. There are several tools available for this, including [CutePDF] and [BullZip]. As IBM employees switch from Microsoft Office to IBM's [Lotus Symphony], it has built-in "export-to-PDF" capability as well. People are also going to their local OfficeMax or CartridgeWorld to get their cartridges refilled, rather than purchase new ones. That has to be hurting HP's bottom line.
Don't Forget About Storage Management
The leading storage management suites today are IBM's Tivoli Storage Productivity Center and EMC's Control Center. HP's Storage Essentials doesn't quite beat either of these, and management software is growing in importance to more and more customers.
A long time ago, perhaps in the early 1990s, I was an architect on the component known today as DFSMShsm on z/OS mainframe operationg system. One of my job responsibilities was to attend the biannual [SHARE conference to listen to the requirements of the attendees on what they would like added or changed to the DFSMS, and ask enough questions so that I can accurately present the reasoning to the rest of the architects and software designers on my team. One person requested that the DFSMShsm RELEASE HARDCOPY should release "all" the hardcopy. This command sends all the activity logs to the designated SYSOUT printer. I asked what he meant by "all", and the entire audience of 120 some attendees nearly fell on the floor laughing. He complained that some clever programmer wrote code to test if the activity log contained only "Starting" and "Ending" message, but no error messages, and skip those from being sent to SYSOUT. I explained that this was done to save paper, good for the environment, and so on. Again, howls of laughter. Most customers reroute the SYSOUT from DFSMS from a physical printer to a logical one that saves the logs as data sets, with date and time stamps, so having any "skipped" leaves gaps in the sequence. The client wanted a complete set of data sets for his records. Fair enough.
When I returned to Tucson, I presented the list of requests, and the immediate reaction when I presented the one above was, "What did he mean by ALL? Doesn't it release ALL of the logs already?" I then had to recap our entire dialogue, and then it all made sense to the rest of the team. At the following SHARE conference six months later, I was presented with my own official "All" tee-shirt that listed, and I am not kidding, some 33 definitions for the word "all", in small font covering the front of the shirt.
I am reminded of this story because of the challenges explaining complicated IT concepts using the English language which is so full of overloaded words that have multiple meanings. Take for example the word "protect". What does it mean when a client asks for a solution or system to "protect my data" or "protect my information". Let's take a look at three different meanings:
The first meaning is to protect the integrity of the data from within, especially from executives or accountants that might want to "fudge the numbers" to make quarterly results look better than they are, or to "change the terms of the contract" after agreements have been signed. Clients need to make sure that the people authorized to read/write data can be trusted to do so, and to store data in Non-Erasable, Non-Rewriteable (NENR) protected storage for added confidence. NENR storage includes Write-Once, Read-Many (WORM) tape and optical media, disk and disk-and-tape blended solutions such as the IBM Grid Medical Archive Solution (GMAS) and IBM Information Archive integrated system.
The second meaning is to protect access from without, especially hackers or other criminals that might want to gather personally-identifiably information (PII) such as social security numbers, health records, or credit card numbers and use these for identity theft. This is why it is so important to encrypt your data. As I mentioned in my post [Eliminating Technology Trade-Offs], IBM supports hardware-based encryption FDE drives in its IBM System Storage DS8000 and DS5000 series. These FDE drives have an AES-128 bit encryption built-in to perform the encryption in real-time. Neither HDS or EMC support these drives (yet). Fellow blogger Hu Yoshida (HDS) indicates that their USP-V has implemented data-at-rest in their array differently, using backend directors instead. I am told EMC relies on the consumption of CPU-cycles on the host servers to perform software-based encryption, either as MIPS consumed on the mainframe, or using their Powerpath multi-pathing driver on distributed systems.
There is also concern about internal employees have the right "need-to-know" of various research projects or upcoming acquisitions. On SANs, this is normally handled with zoning, and on NAS with appropriate group/owner bits and access control lists. That's fine for LUNs and files, but what about databases? IBM's DB2 offers Label-Based Access Control [LBAC] that provides a finer level of granularity, down to the row or column level. For example, if a hospital database contained patient information, the doctors and nurses would not see the columns containing credit card details, the accountants would not see the columnts containing healthcare details, and the individual patients, if they had any access at all, would only be able to access the rows related to their own records, and possibly the records of their children or other family members.
The third meaning is to protect against the unexpected. There are lots of ways to lose data: physical failure, theft or even incorrect application logic. Whatever the way, you can protect against this by having multiple copies of the data. You can either have multiple copies of the data in its entirety, or use RAID or similar encoding scheme to store parts of the data in multiple separate locations. For example, with RAID-5 rank containing 6+P+S configuration, you would have six parts of data and one part parity code scattered across seven drives. If you lost one of the disk drives, the data can be rebuilt from the remaining portions and written to the spare disk set aside for this purpose.
But what if the drive is stolen? Someone can walk up to a disk system, snap out the hot-swappable drive, and walk off with it. Since it contains only part of the data, the thief would not have the entire copy of the data, so no reason to encrypt it, right? Wrong! Even with part of the data, people can get enough information to cause your company or customers harm, lose business, or otherwise get you in hot water. Encryption of the data at rest can help protect against unauthorized access to the data, even in the case when the data is scattered in this manner across multiple drives.
To protect against site-wide loss, such as from a natural disaster, fire, flood, earthquake and so on, you might consider having data replicated to remote locations. For example, IBM's DS8000 offers two-site and three-site mirroring. Two-site options include Metro Mirror (synchronous) and Global Mirror (asynchronous). The three-site is cascaded Metro/Global Mirror with the second site nearby (within 300km) and the third site far away. For example, you can have two copies of your data at site 1, a third copy at nearby site 2, and two more copies at site 3. Five copies of data in three locations. IBM DS8000 can send this data over from one box to another with only a single round trip (sending the data out, and getting an acknowledgment back). By comparison, EMC SRDF/S (synchronous) takes one or two trips depending on blocksize, for example blocks larger than 32KB require two trips, and EMC SRDF/A (asynchronous) always takes two trips. This is important because for many companies, disk is cheap but long-distance bandwidth is quite expensive. Having five copies in three locations could be less expensive than four copies in four locations.
Fellow blogger BarryB (EMC Storage Anarchist) felt I was unfair pointing out that their EMC Atmos GeoProtect feature only protects against "unexpected loss" and does not eliminate the need for encryption or appropriate access control lists to protect against "unauthorized access" or "unethical tampering".
(It appears I stepped too far on to ChuckH's lawn, as his Rottweiler BarryB came out barking, both in the [comments on my own blog post], as well as his latest titled [IBM dumbs down IBM marketing (again)]. Before I get another rash of comments, I want to emphasize this is a metaphor only, and that I am not accusing BarryB of having any canine DNA running through his veins, nor that Chuck Hollis has a lawn.)
As far as I know, the EMC Atmos does not support FDE disks that do this encryption for you, so you might need to find another way to encrypt the data and set up the appropriate access control lists. I agree with BarryB that "erasure codes" have been around for a while and that there is nothing unsafe about using them in this manner. All forms of RAID-5, RAID-6 and even RAID-X on the IBM XIV storage system can be considered a form of such encoding as well. As for the amount of long-distance bandwidth that Atmos GeoProtect would consume to provide this protection against loss, you might question any cost savings from this space-efficient solution. As always, you should consider both space and bandwidth costs in your total cost of ownership calculations.
Of course, if saving money is your main concern, you should consider tape, which can be ten to twenty times cheaper than disk, affording you to keep a dozen or more copies, in as many time zones, at substantially lower cost. These can be encrypted and written to WORM media for even more thorough protection.
Well, it's Tuesday again, and that means IBM announcements! Right on the heels of our big storage launch on February 9, today IBM announced some exciting options for its modular disk systems. Let's take a look:
2TB SATA-II drives
That's right, you can now DOUBLE your capacity with 2TB SATA type-II drives on the DS3950, DS4200, DS4700, DS5020, DS5100 and DS5300 disk controllers, as well as the DS4000 EXP420, EXP520, EXP810, EXP5000 and EXP5060 expansion drawers. Here are the Announcement Letters for the [HVEC] and [AAS] ordering systems.
300GB Solid State Drives
IBM also announces 300GB solid state drives (SSD) for the DS5100 and DS5300. These are four times larger than the 73GB drives IBM offered last year, for those workloads that need high read IOPS such as Online Transaction Processing (OLTP) and Enterprise Resource Planning (ERP) applications. Here is the [Announcement Letter].
New N series model N3400
For customers that need less than the minimum 21TB that our IBM Scale-Out Network Attach Storage (SONAS) can provide, IBM offers the new N3400 unified storage disk system, with support for NFS, CIFS, iSCSI and FCP. This is a 2U high 12 drive model that can be expanded up to 136 drives, basically doubling all the stats from last year's N3300 model. Fellow blogger, Rich Swain (IBM), does a great job recapping the speeds and feeds over on his blog [News and Information about IBM N series].
It also appears that the reports and rumors of the death of the DS6800 are premature. Don't believe misleading statements from competitors, such as those found written by fellow blogger BarryB (EMC), aka "the Storage Anarchist", in his latest post [Bring Out Your Dead] showing a cute little tombstone with "Feb 2010" on the bottom. Actually, if he had bothered to read IBM's [Announcement Letter], he would have realized that IBM plans to continue to sell these until June. Of course, IBM will continue to support both new and existing DS6800 customers for many years to come.
Technically, BarryB does not make any factually incorrect statements for me to correct on his blog. The idea that a product is "dead" is, of course, just opinion, and competitors poke fun at each others' announcements every day. One could argue that the EMC V-Max was "dead" after the ITG whitepaper [Cost/Benefit Case for IBM XIV Storage System - Comparing Costs for IBM XIV and EMC V-Max Systems] demonstrated that the IBM XIV cost 63 percent less than a comparable EMC V-Max over the life of three years total cost of ownership (TCO) back in July 2009. The comparison was made with data from clients in a variety of industries including manufacturing, health care, life sciences, telecommunications, financial services, and the public sector. This could explain why so many EMC customers are buying or investigating the IBM XIV and the rest of the IBM storage portfolio.
The technology industry is full of trade-offs. Take for example solar cells that convert sunlight to electricity. Every hour, more energy hits the Earth in the form of sunlight than the entire planet consumes in an entire year. The general trade-off is between energy conversion efficiency versus abundance of materials:
Get 9-11 percent efficiency using rare materials like indium (In), gallium (Ga) or cadmium (Cd).
Get only 6.7 percent efficiency using abundant materials like copper (Cu), tin (Sn), zinc (Zn), sulfur (S), and selenium (Se)
A second trade-off is exemplified by EMC's recent GeoProtect announcement. This appears similar to the geographic dispersal method introduced by a company called [CleverSafe]. The trade-off is between the amount of space to store one or more copies of data and the protection of data in the event of disaster. Here's an excerpt from fellow blogger Chuck Hollis (EMC) titled ["Cloud Storage Evolves"]:
"Imagine a average-sized Atmos network of 9 nodes, all in different time zones around the world. And imagine that we were using, say, a 6+3 protection scheme.
The implication is clear: any 3 nodes could be completely lost: failed, destroyed, seized by the government, etc.
-- and the information could be completely recovered from the surviving nodes."
For organizations worried about their information falling into the wrong hands (whether criminal or government sponsored!), any subset of the nodes would yield nothing of value -- not only would the information be presumably encrypted, but only a few slices of a far bigger picture would be lost.
Seized by the government?falling into the wrong hands? Is EMC positioning ATMOS as "Storage for Terrorists"? I can certainly appreciate the value of being able to protect 6PB of data with only 9PB of storage capacity, instead of keeping two copies of 6PB each, the trade-off means that you will be accessing the majority of your data across your intranet, which could impact performance. But, if you are in an illicit or illegal business that could have a third of your facilities "seized by the government", then perhaps you shouldn't house your data centers there in the first place. Having two copies of 6PB each, in two "friendly nations", might make more sense.
(In reality, companies often keep way more than just two copies of data. It is not unheard of for companies to keep three to five copies scattered across two or three locations. Facebook keeps SIX copies of photographs you upload to their website.)
ChuckH argues that the governments that seize the three nodes won't have a complete copy of the data. However, merely having pieces of data is enough for governments to capture terrorists. Even if the striping is done at the smallest 512-byte block level, those 512 bytes of data might contain names, phone numbers, email addresses, credit cards or social security numbers. Hackers and computer forensics professionals take advantage of this.
You might ask yourself, "Why not just encrypt the data instead?" That brings me to the third trade-off, protection versus application performance. Over the past 30 years, companies had a choice, they could encrypt and decrypt the data as needed, using server CPU cycles, but this would slow down application processing. Every time you wanted to read or update a database record, more cycles would be consumed. This forced companies to be very selective on what data they encrypted, which columns or fields within a database, which email attachments, and other documents or spreadsheets.
An initial attempt to address this was to introduce an outboard appliance between the server and the storage device. For example, the server would write to the appliance with data in the clear, the appliance would encrypt the data, and pass it along to the tape drive. When retrieving data, the appliance would read the encrypted data from tape, decrypt it, and pass the data in the clear back to the server. However, this had the unintended consequences of using 2x to 3x more tape cartridges. Why? Because the encrypted data does not compress well, so tape drives with built-in compression capabilities would not be able to shrink down the data onto fewer tapes.
(I covered the importance of compressing data before encryption in my previous blog post
[Sock Sock Shoe Shoe].)
Like the trade-off between energy efficiency and abundant materials, IBM eliminated the trade-off by offering compression and encryption on the tape drive itself. This is standard 256-bit AES encryption implemented on a chip, able to process the data as it arrives at near line speed. So now, instead of having to choose between protecting your data or running your applications with acceptable performance, you can now do both, encrypt all of your data without having to be selective. This approach has been extended over to disk drives, so that disk systems like the IBM System Storage DS8000 and DS5000 can support full-disk-encryption [FDE] drives.