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Tony Pearson is a Master Inventor and Senior IT Specialist for the IBM System Storage product line at the
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Have you ever noticed that sometimes two movies come out that seem eerily similar to each other, released by different studios within months or weeks of each other? My sister used to review film scripts for a living, she would read ten of them and have to pick her top three favorites, and tells me that scripts for nearly identical concepts came all the time. Here are a few of my favorite examples:
1994: [Wyatt Earp] and [Tombstone] were Westerns recounting the famed gunfight at the O.K. Corral. Tombstone, Arizona is near Tucson, and the gunfight is recreated fairly often for tourists.
1998: [Armageddon] and [Deep Impact] were a pair of disaster movies dealing with a large rock heading to destroy all life on earth. I was in Mazatlan, Mexico to see the latter, dubbed in Spanish as "Impacto Profundo".
1998: [A Bug's Life] and [Antz] were computer-animated tales of the struggle of one individual ant in an ant colony.
2000: [Mission to Mars] and [Red Planet] were sci-fi pics exploring what a manned mission to our neighboring planet might entail.
This is different than copy-cat movies that are re-made or re-imagined many years later based on the previous successes of an original. Ever since my blog post [VPLEX: EMC's Latest Wheel is Round] in 2010 comparing EMC's copy-cat product that came our seven years after IBM's SAN Volume Controller (SVC), I've noticed EMC doesn't talk about VPLEX that much anymore.
This week, IBM announced [XIV Gen3 Solid-State Drive support] and our friends over at EMC announced [VFCache SSD-based PCIe cards]. Neither of these should be a surprise to anyone who follows the IT industry, as IBM had announced its XIV Gen3 as "SSD-Ready" last year specifically for this purpose, and EMC has been touting its "Project Lightning" since last May.
Fellow blogger Chuck Hollis from EMC has a blog post [VFCache means Very Fast Cache indeed] that provides additional detail. Chuck claims the VFCache is faster than popular [Fusion-IO PCIe cards] available for IBM servers. I haven't seen the performance spec sheets, but typically SSD is four to five times slower than the DRAM cache used in the XIV Gen3. The VFCache's SSD is probably similar in performance to the SSD supported in the IBM XIV Gen3, DS8000, DS5000, SVC, N series, and Storwize V7000 disk systems.
Nonetheless, I've been asked my opinions on the comparison between these two announcements, as they both deal with improving application performance through the use of Solid-State Drives as an added layer of read cache.
(FTC Disclosure: I am both a full-time employee and stockholder of the IBM Corporation. The U.S. Federal Trade Commission may consider this blog post as a paid celebrity endorsement of IBM servers and storage systems. This blog post is based on my interpretation and opinions of publicly-available information, as I have no hands-on access to any of these third-party PCIe cards. I have no financial interest in EMC, Fusion-IO, Texas Memory Systems, or any other third party vendor of PCIe cards designed to fit inside IBM servers, and I have not been paid by anyone to mention their name, brands or products on this blog post.)
The solutions are different in that IBM XIV Gen3 the SSD is "storage-side" in the external storage device, and EMC VFCache is "server-side" as a PCI Express [PCIe] card. Aside from that, both implement SSD as an additional read cache layer in front of spinning disk to boost performance. Neither is an industry first, as IBM has offered server-side SSD since 2007, and IBM and EMC have offered storage-side SSD in many of their other external storage devices. The use of SSD as read cache has already been available in IBM N series using [Performance Accelerator Module (PAM)] cards.
IBM has offered cooperative caching synergy between its servers and its storage arrays for some time now. The predecessor to today's POWER7-based were the iSeries i5 servers that used PCI-X IOP cards with cache to connect i5/OS applications to IBM's external disk and tape systems. To compete in this space, EMC created their own PCI-X cards to attach their own disk systems. In 2006, IBM did the right thing for our clients and fostered competition by entering in a [Landmark agreement] with EMC to [license the i5 interfaces]. Today, VIOS on IBM POWER systems allows a much broader choice of disk options for IBM i clients, including the IBM SVC, Storwize V7000 and XIV storage systems.
Can a little SSD really help performance? Yes! An IBM client running a [DB2 Universal Database] cluster across eight System x servers was able to replace an 800-drive EMC Symmetrix by putting eight SSD Fusion-IO cards in each server, for a total of 64 Solid-State drives, saving money and improving performance. DB2 has the Data Partitioning Feature that has multi-system DB2 configurations using a Grid-like architecture similar to how XIV is designed. Most IBM System x and BladeCenter servers support internal SSD storage options, and many offer PCIe slots for third-party SSD cards. Sadly, you can't do this with a VFCache card, since you can have only one VFCache card in each server, the data is unprotected, and only for ephemeral data like transaction logs or other temporary data. With multiple Fusion-IO cards in an IBM server, you can configure a RAID rank across the SSD, and use it for persistent storage like DB2 databases.
Here then is my side-by-side comparison:
IBM XIV Gen3 SSD Caching
Selected x86-based models of Cisco UCS, Dell PowerEdge, HP ProLiant DL, and IBM xSeries and System x servers
All of these, plus any other blade or rack-optimized server currently supported by XIV Gen3, including Oracle SPARC, HP Titanium, IBM POWER systems, and even IBM System z mainframes running Linux
Operating System support
Linux RHEL 5.6 and 5.7, VMware vSphere 4.1 and 5.0, and Windows 2008 x64 and R2.
All of these, plus all the other operating systems supported by XIV Gen3, including AIX, IBM i, Solaris, HP-UX, and Mac OS X
FCP and iSCSI
Vendor-supplied driver required on the server
Yes, the VFCache driver must be installed to use this feature.
No, IBM XIV Gen3 uses native OS-based multi-pathing drivers.
External disk storage systems required
None, it appears the VFCache has no direct interaction with the back-end disk array, so in theory the benefits are the same whether you use this VFCache card in front of EMC storage or IBM storage
XIV Gen3 is required, as the SSD slots are not available on older models of IBM XIV.
Shared disk support
No, VFCache has to be disabled and removed for vMotion to take place.
Yes! XIV Gen3 SSD caching shared disk supports VMware vMotion and Live Partition Mobility.
Support for multiple servers
An advantage of the XIV Gen3 SSD caching approach is that the cache can be dynamically allocated to the busiest data from any server or servers.
Support for active/active server clusters
Aware of changes made to back-end disk
No, it appears the VFCache has no direct interaction with the back-end disk array, so any changes to the data on the box itself are not communicated back to the VFCache card itself to invalidate the cache contents.
None identified. However, VFCache only caches blocks 64KB or smaller, so any sequential processing with larger blocks will bypass the VFCache.
Yes! XIV algorithms detect sequential access and avoid polluting the SSD with these blocks of data.
Number of SSD supported
One, which seems odd as IBM supports multiple Fusion-IO cards for its servers. However, this is not really a single point of failure (SPOF) as an application experiencing a VFCache failure merely drops down to external disk array speed, no data is lost since it is only read cache.
6 to 15 (one per XIV module) for high availability.
Pin data in SSD cache
Yes, using split-card mode, you can designate a portion of the 300GB to serve as Direct-attached storage (DAS). All data written to the DAS portion will be kept in SSD. However, since only one card is supported per server and the data is unprotected, this should only be used for ephemeral data like logs and temp files.
No, there is no option to designate an XIV Gen3 volume to be SSD-only. Consider using Fusion-IO PCIe card as a DAS alternative, or another IBM storage system for that requirement.
Pre-sales Estimating tools
Yes! CDF and Disk Magic tools are available to help cost-justify the purchase of SSD based on workload performance analysis.
IBM has the advantage that it designs and manufactures both servers and storage, and can design optimal solutions for our clients in that regard.
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.
If you store your VMware bits on external SAN or NAS-based disk storage systems, this post is for you. The subject of the post, VM Volumes, is a potential storage management game changer!
Fellow blogger Stephen Foskett mentioned VM Volumes in his [Introducing VMware vSphere Storage Features] presentation at IBM Edge 2012 conference. His session on VMware's storage features included VMware APIs for Array Integration (VAAI), VMware Array Storage Awareness (VASA), vCenter plug-ins, and a new concept he called "vVol", now more formally known as VM Volumes. This post provides a follow-up to this, describing the VM Volumes concepts, architecture, and value proposition.
"VM Volumes" is a future architecture that VMware is developing in collaboration with IBM and other major storage system vendors. So far, very little information about VM Volumes has been released. At VMworld 2012 Barcelona, VMware highlights VM Volumes for the first time and IBM demonstrates VM Volumes with the IBM XIV Storage System (more about this demo below). VM Volumes is worth your attention -- when it becomes generally available, everyone using storage arrays will have to reconsider their storage management practices in a VMware environment -- no exaggeration!
But enough drama. What is this all about?
(Note: for the sake of clarity, this post refers to block storage only. However, the VM Volumes feature applies to NAS systems as well. Special thanks to Yossi Siles and the XIV development team for their help on this post!)
The VM Volumes concept is simple: VM disks are mapped directly to special volumes on a storage array system, as opposed to storing VMDK files on a vSphere datastore.
The following images illustrate the differences between the two storage management paradigms.
You may still be asking yourself: bottom line, how will I benefit from VM Volumes?
Well, take a VM snapshot for example. With VM Volumes, vSphere can simply offload the operation by invoking a hardware snapshot of the hardware volume. This has significant implications:
VM-Granularity: Only the right VMs are copied (with datastores, backing up or cloning individual-VM portions of hardware snapshot of a datastore would require more complex configuration, tools and work)
Hardware Offload: No ESXi server resources are consumed
XIV advantage: With XIV, snapshots consume no space upfront and are completed instantly.
Here's the first takeaway: With VM Volumes, advanced storage services (which cost a lot when you buy a storage array), will become available at an individual VM level. In a cloud world, this means that applications can be provisioned easily with advanced storage services, such as snapshots and mirroring.
Now, let's take a closer look at another relevant scenario where VM Volumes will make a lot of difference - provisioning an application with special mirroring requirements:
VM Volumes case: The application is ordered via the private cloud portal. The requestor checks a box requesting an asynchronous mirror. He changes the default RPO for his needs. When the request is submitted, the process wraps up automatically: Volumes are created on one of the storage arrays, configured with a mirror and RPO exactly as specified. A few minutes later, the requestor receives an automatic mail pointing to the application virtual machine.
Datastores case #1: As may be expected, a datastore that is mirrored with the special RPO does not exist. As a result, the automated workflow sets a pending status on the request, creates an urgent ticket to a VMware administrator and aborts. When the VMware admin handles that ticket, she re-assigns the ticket to the storage administrator, asking for a new volume which is mirrored with the special RPO, and mapped to the right ESXi cluster. The next day, the volume is created; the ticket is re-assigned to the storage admin, with the new LUN being pointed to. The VMware administrator follows and creates the datastore on top of it. Since the automated workflow was aborted, the admin re-assigns the ticket to the cloud administrator, who sometime later completes the application provisioning manually.
Datastores case #2: Luckily for the requestor, a datastore that is mirrored with the special RPO does exist. However, that particular datastore is consuming space from a high performance XIV Gen3 system with SSD caching, while the application does not require that level of performance, so the workflow requires a storage administrator approval. The approval is given to save time, but the storage administrator opens a ticket for himself to create a new volume on another array, as well as a follow-up ticket for the VMware admin to create a new datastore using the new volume and migrate the application to the other datastore. In this case, provisioning was relatively rapid, but required manual follow up, involving the two administrators.
Here's the second takeaway: With VM Volumes, management is simplified, and end-to-end automation is much more applicable. The reason is that there are no datastores. Datastores physically group VMs that may otherwise be totally unrelated, and require close coordination between storage and VMware administrators.
Now, the above mainly focuses on the VMware or cloud administrator perspective. How does VM Volumes impact storage management?
VM's are the new hosts: Today, storage administrators have visibility of physical hosts in their management environment. In a non-virtualized environment, this visibility is very helpful. The storage administrator knows exactly which applications in a data center are storage-provisioned or affected by storage management operations because the applications are running on well-known hosts. However, in virtualized environments the association of an application to a physical host is temporary. To keep at least the same level of visibility as in physical environments, VMs should become part of the storage management environment, like hosts. Hosts are still interesting, for example to manage physical storage mapping, but without VM visibility, storage administrators will know less about their operation than they are used to, or need to. VM Volumes enables such visibility, because volumes are provided to individual VMs. The XIV VM Volumes demonstration at VMworld Barcelona, although experimental, shows a view of VM volumes, in XIV's management GUI.
Here's a screenshot:
That's not all!
Storage Profiles and Storage Containers: A Storage Profile is a vSphere specification of a set of storage services. A storage profile can include properties like thin or thick provisioning, mirroring definition, snapshot policy, minimum IOPS, etc.
Storage administrators define a portfolio of supported storage services, maintained as a set of storage profiles, and published (via VASA integration) to vSphere.
VMware or cloud administrators define the required storage profiles for specific applications
VMware and storage administrators need to coordinate the typical storage requirements and the automatically-available storage services. When a request to provision an application is made, the associated storage profiles are matched against the published set of available storage profiles. The matching published profiles will be used to create volumes, which will be bound to the application VMs. All that will happen automatically.
Note that when a VM is created today, a datastore must be specified. With VM Volumes, a new management entity called Storage Container (also known as Capacity Pool) replaces the use of datastore as a management object. Each Storage Container exposes a subset of the available storage profiles, as appropriate. The storage container also has a capacity quota.
Here are some more takeaways:
New way to interface vSphere and storage management: Storage administrators structure and publish storage services to vSphere via storage profiles and storage containers.
Automated provisioning, out of the box: The provisioning process automatically matches application-required storage profiles against storage profiles available from the specified storage containers. There is no need to build custom scripts and custom processes to automate storage provisioning to applications
The XIV advantage:
XIV services are very simple to define and publish. The typical number of available storage profiles would be low. It would also be easy to define application storage profiles.
XIV provides consistent high performance, up to very high capacity utilization levels, without any maintenance. As a result, automated provisioning (which inherently implies less human attention) will not create an elevated risk of reduced performance.
Note: A storage vendor VASA provider is required to support VM Volumes, storage profiles, storage containers and automated provisioning. The IBM Storage VASA provider runs as a standalone service that needs to be deployed on a server.
To summarize the VM Volumes value proposition:
Streamline cloud operation by providing storage services at VM and application level, enabling end-to-end provisioning automation, and unifying VMware and storage administration around volumes and VMs.
Increase storage array ROI, improve vSphere scalability and response time, and reduce cloud provisioning lag, by offloading VM-level provisioning, failover, backup, storage migration, storage space recycling, monitoring, and more, to the storage array, using advanced storage operations such as mirroring and snapshots.
Simplify the adoption of VM Volumes using XIV, with smaller and simpler sets of storage profiles. Apply XIV's supreme fast cloning to individual VMs, and keep automation risks at bay with XIV's consistent high performance.
Until you can get your hands on a VM Volumes-capable environment, the VMware and IBM developer groups will be collaborating and working hard to realize this game-changing feature. The above information is definitely expected to trigger your questions or comments, and our development teams are eager to learn from them and respond. Enter your comments below, and I will try to answer them, and help shape the next post on this subject. There's much more to be told.
A client asked me to explain "Nearline storage" to them. This was easy, I thought, as I started my IBM career on DFHSM, now known as DFSMShsm for z/OS, which was created in 1977 to support the IBM 3850 Mass Storage System (MSS), a virtual storage system that blended disk drives and tape cartridges with robotic automation. Here is a quick recap:
Online storage is immediately available for I/O. This includes DRAM memory, solid-state drives (SSD), and always-on spinning disk, regardless of rotational speed.
Nearline storage is not immediately available, but can be made online quickly without human intervention. This includes optical jukeboxes, automated tape libraries, as well as spin-down massive array of idle disk (MAID) technologies.
Offline storage is not immediately available, and requires some human intervention to bring online. This can include USB memory sticks, CD/DVD optical media, shelf-resident tape cartridges, or other removable media.
Sadly, it appears a few storage manufacturers and vendors have been misusing the term "Nearline" to refer to "slower online" spinning disk drives. I find this [June 2005 technology paper from Seagate], and this [2002 NetApp Press Release], the latter of which included this contradiction for their "NearStore" disk array. Here is the excerpt:
"Providing online access to reference information—NetApp nearline storage solutions quickly retrieve and replicate reference and archive information maintained on cost-effective storage—medical images, financial models, energy exploration charts and graphs, and other data-intensive records can be stored economically and accessed in multiple locations more quickly than ever"
Which is it, "online access" or "nearline storage"?
If a client asked why slower drives consume less energy or generate less heat, I could explain that, but if they ask why slower drives must have SATA connections, that is a different discussion. The speed of a drive and its connection technology are for the most part independent. A 10K RPM drive can be made with FC, SAS or SATA connection.
I am opposed to using "Nearlne" just to distinguish between four-digit speeds (such as 5400 or 7200 RPM) versus "online" for five-digit speeds (10,000 and 15,000 RPM). The difference in performance between 10K RPM and 7200 RPM spinning disks is miniscule compared to the differences between solid-state drives and any spinning disk, or the difference between spinning disk and tape.
I am also opposed to using the term "Nearline" for online storage systems just because they are targeted for the typical use cases like backup, archive or other reference information that were previously directed to nearline devices like automated tape libraries.
Can we all just agree to refer to drives as "fast" or "slow", or give them RPM rotational speed designations, rather than try to incorrectly imply that FC and SAS drives are always fast, and SATA drives are always slow? Certainly we don't need new terms like "NL-SAS" just to represent a slower SAS connected drive.
My series last week on IBM Watson (which you can read [here], [here], [here], and [here]) brought attention to IBM's Scale-Out Network Attached Storage [SONAS]. IBM Watson used a customized version of SONAS technology for its internal storage, and like most of the components of IBM Watson, IBM SONAS is commercially available as a stand-alone product.
Like many IBM products, SONAS has gone through various name changes. First introduced by Linda Sanford at an IBM SHARE conference in 2000 under the IBM Research codename Storage Tank, it was then delivered as a software-only offering SAN File System, then as a services offering Scale-out File Services (SoFS), and now as an integrated system appliance, SONAS, in IBM's Cloud Services and Systems portfolio.
If you are not familiar with SONAS, here are a few of my previous posts that go into more detail:
This week, IBM announces that SONAS has set a world record benchmark for performance, [a whopping 403,326 IOPS for a single file system]. The results are based on comparisons of publicly available information from Standard Performance Evaluation Corporation [SPEC], a prominent performance standardization organization with more than 60 member companies. SPEC publishes hundreds of different performance results each quarter covering a wide range of system performance disciplines (CPU, memory, power, and many more). SPECsfs2008_nfs.v3 is the industry-standard benchmark for NAS systems using the NFS protocol.
(Disclaimer: Your mileage may vary. As with any performance benchmark, the SPECsfs benchmark does not replicate any single workload or particular application. Rather, it encapsulates scores of typical activities on a NAS storage system. SPECsfs is based on a compilation of workload data submitted to the SPEC organization, aggregated from tens of thousands of fileservers, using a wide variety of environments and applications. As a result, it is comprised of typical workloads and with typical proportions of data and metadata use as seen in real production environments.)
The configuration tested involves SONAS Release 1.2 on 10 Interface Nodes and 8 Storage Pods, resulting a single file system over 900TB usable capacity.
10 Interface Nodes; each with:
Maximum 144 GB of memory
One active 10GbE port
8 Storage Pods; each with:
2 Storage nodes and 240 drives
Drive type: 15K RPM SAS hard drives
Data Protection using RAID-5 (8+P) ranks
Six spare drives per Storage Pod
IBM wanted a realistic "no compromises" configuration to be tested, by choosing:
Regular 15K RPM SAS drives, rather than a silly configuration full of super-expensive Solid State Drives (SSD) to plump up the results.
Moderate size, typical of what clients are asking for today. The Goldilocks rule applies. This SONAS is not a small configuration under 100TB, and nowhere close to the maximum supported configuration of 7,200 disks across 30 Interface Nodes and 30 Storage Pods.
Single file system, often referred to as a global name space, rather than using an aggregate of smaller file systems added together that would be more complicated to manage. Having multiple file systems often requires changes to applications to take advantage of the aggregate peformance. It is also more difficult to load-balance your performance and capacity across multiple file systems. Of course, SONAS can support up to 256 separate file systems if you have a business need for this complexity.
The results are stunning. IBM SONAS handled three times more workload for a single file system than the next leading contender. All of the major players are there as well, including NetApp, EMC and HP.