Continuing my ongoing discussion on Solid State Disk (SSD), fellow blogger BarryB (EMC) points out in his [latest post
Oh – and for the record TonyP, I don't think I ever said EMC was using a newer or different EFDs than IBM. I just asserted that EMC knows more than IBM about these EFDs and how they actually work a storage array under real-world workloads.
(Here "EFD" is refers to "Enterprise Flash Drive", EMC's marketing term for Single Layer Cell (SLC) NAND Flash non-volatile solid-state storage devices. Both IBM and EMC have been selling solid-state storage for quite some time now, but EMC felt that a new term was required to distinguish the SLC NAND Flash devices sold in their disk systems from solid-state devices sold in laptops or blade servers. The rest of the industry, including IBM, continues to use the term SSD to refer to these same SLC NAND Flash devices that EMC is referring to.)
The disagreement resulted from his earlier statement from his post[IBM's amazing...part deux]:
Although STEC asserts that IBM is using the latest ZeusIOPS drives, IBM is only offering the 73GB and 146GB STEC drives (EMC is shipping the latest ZeusIOPS drives in 200GB and 400GB capacities for DMX4 and V-Max, affording customers a lower $/GB, higher density and lower power/footprint per usable GB.)
Here is where I enjoy the subtleties between marketing and engineering. Does the above seem like he is saying EMC is using newer or different drives? What are typical readers expected to infer from the statement above?
- That there are four different drives from STEC, in four different capacities. In the HDD world, drives of different capacities are often different, and larger capacities are often newer than those of smaller capacities.
- That the 200GB and 400GB are the latest drives, and that 73GB and 146GB drives are not the latest.
- That STEC press release is making false or misleading claims.
Uncontested, some readers might infer the above and come to the wrong conclusions. I made an effort to set the record straight. I'll summarize with a simple table:
|Raw capacity||128 GB||256 GB||512 GB|
|Usable (conservative format)||73 GB||146 GB||300 GB|
|Usable (aggressive format)||100 GB||200 GB||400 GB|
So, we all agree now that the 256GB drives that are formatted as 146GB or 200GB are in fact the same drives, that IBM and EMC both sell the latest drives offered by STEC, and that the STEC press release was in fact correct in its claims.
I also wanted to emphasize that IBM chose the more conservative format on purpose. BarryB [did the math himself] and proved my key points:
- Under some write-intensive workloads, an aggressive format may not last the full five years. (But don't worry, BarryB assures us that EMC monitors these drives and replaces them when they fail within the five years under their warranty program.)
- Conservative formats with double the spare capacity happen to have roughly double the life expectancy.
I agree with BarryB that an aggressive format can offer a lower $/GB than the conservative format. Cost-conscious consumers often look for less-expensive alternatives, and are often willing to accept less-reliable or shorter life expectancy as a trade-off. However, "cost-conscious" is not the typical EMC targeted customer, who often pay a premiumfor the EMC label. To compensate, EMC offers RAID-6 and RAID-10 configurations to provide added protection. With a conservative format, RAID-5 provides sufficient protection.
(Just so BarryB won't accuse me of not doing my own math, a 7+P RAID-5 using conservative format 146GB drives would provide 1022GB of capacity, versus 4+4 RAID-10 configuration using aggressive format 200GB drives only 800GB total.)
In an ideal world, you the consumer would know exactly how many IOPS your application will generate over the next five years, exactly how much capacity you will require, be offered all three drives in either format to choose from, and make a smart business decision. Nothing, however, is ever this simple in IT.
technorati tags: IBM, SSD, EMC, EFD, SLC, NAND, Flash, disk, storage systems, life expectancy, reliability, capacity, Barry Burke, STEC, IOPS
Looks like fellow blogger and arch nemesis BarryB from EMC is once again stirring up trouble, this time he focuses his attention on IBM's leadership in Solid State Disk (SSD) on the IBM System Storage DS8000 disk systems in his post [IBM's amazing splash dance, part deux
], a follow-up to [IBM's amazing splash dance
] and multi-vendor tirade [don't miss the amazing vendor flash dance
(Note: IBM [Guidelines] prevent me from picking blogfights, so this post is only to set the record straight on some misunderstandings, point to some positive press about IBM's leadership in this area, and for me to provide a different point of view.)
First, let's set the record straight on a few things. The [RedPaper is still in draft form] under review, and so some information has not yet been updated to reflect the current situation.
- You can have 16 or 32 SSD per DA pair. However, you can only have a maximum of 128 SSD drives total in any DS8100 or DS8300. In the case of the IBM DS8300 with 8 DA pairs, it makes more senseto spread the SSD out across all 8 pairs, and perhaps this is what confused BarryB.
- Yes, you can order an all-SSD model of the IBM DS8000 disk system. I don't see anywhere in the RedPaper that suggests otherwise, and I have confirmed with our offering manager that this is the case.
- The 73GB and 146GB are freshly manufactured from STEC. The 146GB drive and 200GB drives are actually the same drive but just formatted differently. The 200GB format does not offer as much spare capacity for wear-leveling, and are therefore intended only for read-intensive workloads. (Perhaps EMC wants you to find this out the hard way so that you replace them more often???) These reduced-spare-capacity formats may not be appropriate with some write-intensive workloads. Don't let anyone from EMC try to misrepresent the 73GB or 146GB drives from STEC as older, obsolete, collecting dust in a warehouse, or otherwise no longer manufactured by STEC.
- You can relocate data from HDD to SSD using "Data Set FlashCopy", a feature that does not involve host-based copy services, does not consume any MIPS on your System z mainframe, and is performed inside the DS8000 disk system. You can also use host-based copy services as well, but it is not the only way.
- You can use any supported level of z/OS with SSD in the IBM DS8000. There is ENHANCED support mentioned in the RedPaper that you get only with z/OS 1.8 and above, allowing you to create automation policies that place data sets onto SSD or non-SSD storage pools. This synergy makes SSD with IBM DS8000 superior to the initial offerings that EMC had offered without this OS support.
I find it amusing that BarryB's basic argument is that IBM's initial release of SSD disk on DS8000 is less than what the potential architecture could be extended to support much more. Actually, if you look at EMC's November release of Atmos, as well as their most recent announcement of V-Max, they basically say the same thing "Stay Tuned, this is just our initial release, with various restrictions and limitations, but more will follow." Architecturally, IBM DS8000 could support a mix of SSD and non-SSD on the same DA pairs, could support RAID6 and RAID10 as well, and could support larger capacity drives or use higher-capacity read-intensive formats. These could all be done via RPQ if needed, or in a follow-on release.
BarryB's second argument is that IBM is somehow "throwing cold water" on SSD technology. That somehow IBM is trying to discourage people from using SSD by offering disk systems with this technology. IBM offered SSD storage on BladeCenter servers LONG BEFORE any EMC disk system offering, and IBM continues to innovate in ways that allow the best business value of this new technology. Take for example this 24-page IBM Technical Brief:[IBM System z® and System Storage DS8000:Accelerating the SAP® Deposits Management Workload With Solid State Drives]. It is full of example configurations that show that SSD on IBM DS8000 can help in practical business applications. IBM takes a solution view, and worked with DB2, DFSMS, z/OS, High Performance FICON (zHPF), and down the stack to optimize performance to provide real business value innovation. Thanks to this synergy,IBM can provide 90 percent of the performance improvement with only 10 percent of the SSD disk capacity as EMC offerings. Now that's innovative!
The price and performance differences between FC and SATA (what EMC was mostly used to) is only 30-50 percent. But the price and performance differences between SSD and HDD is more than an order of magnitude in some cases 10-30x, similar to the differences between HDD and tape. Of course, if you want hybrid solutions that take best advantage of SSD+HDD, it makes more sense to go to IBM, the leading storage vendor that has been doing HDD+Tape hybrid solutions for the past 30 years. IBM understands this better, and has more experience dealing with these orders of magnitude than EMC.
But don't just take my word for it. Here is an excerpt from Jim Handy, from [Objective Analysis] market research firm, in a recent Weekly Review from [Pund-IT] (Volume 5, Issue 23--May 6, 2009):
"What about IBM? One thing that we are finding is that IBM really “Gets It” in the area offlash in the data center. Readers of the Pund-IT Review will not only recall that IBM Researchpushed its SSD-based “Quicksilver” storage system to one million IOPS using Fusion-ioflash-based storage, but they also may have noticed that the recent MySQL and mem-cachedappliances recently introduced by Schooner Information Technology are both flash-enableddevices introduced in partnership with IBM. Ironically, while other OEMs are takingthe cautious approach of introducing a standard SSD option to their systems first, IBM appearsto have been working on several approaches simultaneously to bring flash to thedata center not only in SSDs, but in innovative ways as well."
As for why STEC put out a press release on their own this week without a corresponding IBM press release, I can only say that IBM already announced all of this support back in February, and I blogged about it in my post [Dynamic Infrastructure - Disk Announcements 1Q09]. This is not the first time one of IBM's suppliers has tried to drum up business in this manner. Intel often funds promotions for IBM System x servers (the leading Intel-based servers in the industry) to help drive more business for their Xeon processor.
So, BarryB, perhaps its time for you to take out your green pen and work up another one of your all-too-common retraction and corrections.[Read More]
Continuing my week blogging at the [Forrester IT Forum 2009 conference
] in Las Vegas, Nevada, IBM sponsored Tuesday night's evening reception.
|Bob Moffat, IBM Senior VP and Group Executive who leads IBM's world-renown Systems and Technology Group, and Cris Espinosa, System x and BladeCenter platform sales specialist, one of the many employees like me at the bottom of same Systems and Technology Group.|
|Here'sBob Moffatholding an IBM BladeCenter HS22 blade server.A lot of the IBM executives were on hand to help show off IBM's strategy and vision, and highlight how to deploy IBM systems that are the right fit for today.|
|This is Ira Chavis, IBM consulting IT specialist, who covers how to manage and reduce energy usage today withIBM Energy Efficiency offerings.|
|Here is Casey Bell, our liaison for the conference, and Angela Reese, who presented Tivoli's latest appliances:|
- IBM Tivoli Foundations Application Manager
- IBM Tivoli Foundations Service Manager
These are IBM servers pre-installed with IBM Tivoli software to help monitor applications and provide service desk support. These are part of our IBM Express initiative that focus solutions aimed for medium sized businesses. By offering them as appliances, rather than just software, these can be deployed in only an hour in most situations.
|And here I am, Tony Pearson, IBM certified Dynamic Infrastructure solutions expert, covering servers, storage and networking systems that help to improve service, reduce costs and manage risk. IBM offers flexible systems, software and services to match a wide diversity of business needs, designed for today's challenges and tomorrow's opportunities.|
This was a long day, and looks to be a long week ahead.
technorati tags: IBM, FITF09, Forrester, Forrester Research, FORR, IT Forum, Bob Moffat, Robert Moffat, STG, Ira Chavis, Casey Bell, Angela Reese, Cris Espinosa, Tony Pearson, Dynamic Infrastructure
Continuing my blog coverage of the [Forrester IT Forum 2009 conference
],I will group a bunch of topics related to Cloud Computing into one post. Cloud Computing was a big topichere at the IT Forum, and probably was also in the other two conferences IBM participated in this week inLas Vegas:
The CIOs and IT professionals at this Forrester IT Forum seemed to be IT decision makers with a broader view. There was a lot of interest in Cloud Computing. What is Cloud Computing? Basically, it is renting IT capability on an as-needed basis from a computing service provider. The different levels of cloud computing depends on what the computing service provider actually provides. How do these compare with traditional co-location facilities or your own in-house on-premises computing? Here's my handy-dandy quick-reference guide:
|Cloud Software-as-a-Service [SaaS], Examples: SalesForce and Google Apps.||Yes||Yes||Yes||Yes||No|
|Cloud Platform-as-a-Service [PaaS], such as Google AppEngine, Microsoft Azure, or IBM's own [Computing On Demand].||Yes||Yes||Yes||No||No|
|Cloud Infrastructure-as-a-Service [IaaS], such as Amazon EC2, RackSpace.||Yes||Yes||No||No||No|
|Tradtional Co-Location facility, you park your equipment on rented floorspace, power, cooling and bandwidth.||Yes||No||No||No||No|
|Traditional On-Premises, what most people do today, build or buy your own data center, buy the hardware, write or buy the software, then install and manage it.||No||No||No||No||No|
A main tent session had a moderated Q&A panel of three Forrester Analysts titled "Saving, Making and Risking Cash with Cloud Computing." Here are some key points from this panel:
- Is Cloud Computing just another tool in the IT toolbox, or does it represent a revolution? The panel gave arguments for both. As a set of technology, protocols and standards, it is an evolutionary progression of other standards already in place, and an extension of methods used in co-location and time-share facilities. However,from a business model perspective, Cloud Computing represents a revolutionary trend, eliminating in some cases huge up-front capital expenses and/or long-term outsourcing contracts. PaaS and IaaS offerings can be rented by the hour, for example.
- An example of using Cloud Computing for a one-time batch job: The New York Times decided to build an archive of 11 million articles, but this meant having to convert them all from TIFF to PDF format. The IT person they put in charge of this rented 100 machines on [Amazon Elastic Compute Cloud (EC2)] for 24 hours and was able to convert all 4TB of data for only $240 US dollars.
- Cloud Computing can make it easier for companies to share information with clients, suppliers and business partners, eliminating the need to punch holes through firewalls to provide access.
- Since it is relatively cheap for companies to try out different cloud computing offerings with little or no capital investment, the spaghetti model applies--"throw it on the wall, and see what sticks!"
- What application areas should you consider running in the cloud? Employee self-service portals-Yes, ERP-Mixed, On-time batch jobs-Mixed, Email-Yes, Access Control-No, Web 2.0-Mixed, Testing/QA-Mixed, Back Office Transactions-No, Disaster Recovery-Mixed.
- Different IT roles will see varying benefits and risks with cloud computing. However, by 2011, every new IT project must answer the question "Why not run in the cloud?"
There were a variety of track sessions that explored different aspects of cloud computing:
- Software-as-a-Server: When and Why
This session had three Forrester analysts in a Q&A panel format. SaaS can provide much-needed relief from application support, maintenance and upgrade chores. The choice and depth of offerings is improving from SaaS providers. However, when comparing TCO between SaaS and on-premises deployments, can yield different results for different use cases. For example, a typical SaaS rate of $100 US dollars per user per month, with discounts, could be $1000 per year, or $10,000 over a 10-year period. Compare that to the total 10-year costs of an on-premises deployment, and you have a good ball-park comparison. SaaS can provide faster time-to-value, and you can easily just try-before-you-buy several alternative offerings before making a decision.
The downside to SaaS is that you need to understand their data center, where it is located, and how it is protected for backup and disaster recovery. Some SaaS providers have only a single data center, so it mightbe disruptive if it experiences a regional disaster.
- Cloud IT Services: The Next Big Thing or Just Marketing Vapor?
Economic pressures are forcing companies to explore alternatives, and Cloud IT services are providingadditional options over traditional outsourcing. Only 70-80 percent of companies are satisfied with traditionaloutsourcing, so there is opportunity for Cloud IT services to address those not satisfied. Scalable, consumption-based billing with Web-based accessibility and flexibility is an attractive proposition. Tenyears ago, you could not buy an hour on a mainframe with your credit card, now you can.
Cloud technologies are mature, and there is interest in using these services. About 10 percent of companies are piloting SaaS offerings, 16 percent piloting PaaS offerings, and 13 percent investing in deploying "private clouds" within their data center. This week Aneesh Chopra, who is Barack Obama's pick as the first CTO for the US Federal Government, [stated to congressional leaders]: “The federal government should be exploring greater use of cloud computing where appropriate.”
IBM is betting heavily on their Cloud Computing strategy, has already gone through the reorganizations needed to be positioned well, and claims to have thousands of clients already. HP has some cloud offerings focused on their enterprise customers. Dell is investing and reorganizing for cloud as well.
- Network Strategic Planning for Challenging Times
While not limited to Cloud Computing, companies are seeing WAN traffic doubling every 18 months, but withoutthe corresponding increases in budget to cover it. The Forrester analyst covered WAN optimization management services, hybrid Ethernet-MPLS offerings to help people transition from MPLS VPNs to Carrier-grade Ethernet.
Who should you hire for WAN optimization? Do you trust your own Telco that provides your bandwidth to help you figure out ways to use less of it? Alternatives include System Integrators and Service providers like IBM and EDS.Or, you could try to do it yourself, but this requires capital investment in gear and performance monitoring software.
New workloads like Voice over IP (VoIP) and digital surveillance can help cost-justify upgrading your MPLS VPNs to Carrier-grade Ethernet. The possibility of converging this with iSCSI and/or Fibre Channel (FC) over Ethernet (FCoE) and this can help reduce costs as well. Both MPLS and Ethernet will co-exist for awhile, and hybrid offerings from Telcos will help ease the transition. In the meantime, switching some workloads to Cloud Computing can provide immediate relief to in-house networks now. Converging voice, video, LAN, WAN and SAN traffic may require the IT departments to reorganize how the IT role of "network administrator" is handled.
- Navigating the Myriad New Sourcing Models
The landscape of outsourcing has changed with the introducing of new Cloud Computing offerings. However, adapting these new offerings to internal preferences may prove challenging. The Forrester analyst suggesting being ready to try to influence their companies to adopt Cloud Computing as a new sourcing option.
Traditional outsourcing just manages your existing hardware and software, often referred to as "Your mess for less!" However, outsourcing contract law is mature and many outsource providers are large, well-established providers. In contrast, some SaaS providers are small, and the few that are largemay be fairly new to the outsourcing business. Here are some things to consider:
- Where will the data physically be located? There are government regulations, such as the US Patriot Act, that can influence this decision.Many Canadian and European customers are avoiding providers where datais stored in the United States for this reason.
- What is the service delivery chain? Some cloud providers in turn useother cloud providers. For example a SaaS provider might develop the software and then rent the platform it runs on from a PaaS, which in turn mightbe using offshore or co-location facilities to actually house their equipment.Knowing the service delivery chain may prove important on contractnegotiations. Clarify "cloud" terminology and avoid mixed metaphors.
- What is their contingency plan? What is your contingency plan if the system is slow or inaccessible. What is their plan to protect against data loss during disasters? What if they go out of business? Source Code Escrow has proven impractical in many cases. SLAs should provide for performance, availability and other key metrics. However, service level penalties are not a cure-all for major disruptions, loss of revenues or reputation.
- How will they handle security, compliance and audits? Heavy regulatory requirements may favor dedicated resources to be used.
- Who has "custodianship" of the data? Will you get the data back if you discontinue the contract? If so, what format will it be in, and will it make any sense if you are not running the same application as the cloud provider?
- Will they provide transition assistance? Moving from on-premises to cloud may involve some effort, including re-training of end users.
- Are the resources shared or dedicated? For shared resource environments, is the capacity "fenced off" in any way to prevent having other clients impact your performance or availability.
I am glad to see so much interest in Cloud Computing. To learn more, here is IBM's [Cloud Computing] landing page.
technorati tags: IBM, Las Vegas, FITF09, Forrester, Forrester Research, FORR, IT Forum, Cloud Computing, Manhattan Momentum, Interop, SaaS, PaaS, IaaS, co-location, Amazon EC2, Google, private cloud, SalesForce, Aneesh Chopra, HP, Dell, MPLS, Ethernet, VoIP, Digital Video Surveillance, LAN, WAN, SAN, FCoE, iSCSI
My post last week [Solid State Disk on DS8000 Disk Systems
] kicked up some dust in the comment section.Fellow blogger BarryB (a member of the elite [Anti-Social Media gang from EMC
]) tried to imply that 200GB solid state disk (SSD) drives were different or better than the 146GB drives used in IBM System Storage DS8000 disk systems. I pointed out that they are the actual same physical drive, just formatted differently.
To explain the difference, I will first have to go back to regular spinning Hard Disk Drives (HDD). There are variances in manufacturing, so how do you make sure that a spinning disk has AT LEAST the amount of space you are selling it as? The solution is to include extra. This is the same way that rice, flour, and a variety of other commodities are sold. Legally, if it says you are buying a pound or kilo of flour, then it must be AT LEAST that much to be legal labeling. Including some extra is a safe way to comply with the law. In the case of disk capacity, having some spare capacity and the means to use it follows the same general concept.
(Disk capacity is measured in multiples of 1000, in this case a Gigabyte (GB) = 1,000,000,000 bytes, not to be confused with [Gibibyte (GiB)] = 1,073,741,824 bytes, based on multiples of 1024.)
Let's say a manufacturer plans to sell 146GB HDD. We know that in some cases there might be bad sectors on the disk that won't accept written data on day 1, and there are other marginally-bad sectors that might fail to accept written data a few years later, after wear and tear. A manufacturer might design a 156GB drive with 10GB of spare capacity and format this with a defective-sector table that redirects reads/writes of known bad sectors to good ones. When a bad sector is discovered, it is added to the table, and a new sector is assigned out of the spare capacity.Over time, the amount of space that a drive can store diminishes year after year, and once it drops below its rated capacity, it fails to meet its legal requirements. Based on averages of manufacturing runs and material variances, these could then be sold as 146GB drives, with a life expectancy of 3-5 years.
With Solid State Disk, the technology requires a lot of tricks and techniques to stay above the rated capacity. For example, you can format a 256GB drive as a conservative 146GB usable, with an additional 110GB (75 percent) spare capacity to handle all of the wear-leveling. You could lose up to 22GB of cells per year, and still have the rated capacity for the full five-year life expectancy.
Alternatively, you could take a more aggressive format, say 200GB usable, with only 56GB (28 percent) of spare capacity. If you lost 22GB of cells per year, then sometime during the third year, hopefully under warranty, your vendor could replace the drive with a fresh new one, and it should last the rest of the five year time frame. The failed drive, having 190GB or so usable capacity, could then be re-issued legally as a refurbished 146GB drive to someone else.
The wear and tear on SSD happens mostly during erase-write cycles, so for read-intensive workloads, such as boot disks for operating system images, the aggressive 200GB format might be fine, and might last the full five years.For traditional business applications (70 percent read, 30 percent write) or more write-intensive workloads, IBM feels the more conservative 146GB format is a safer bet.
This should be of no surprise to anyone. When it comes to the safety, security and integrity of our client's data, IBM has always emphasized the conservative approach.[Read More]