EMC VFCache is a Simple Read Cache

I was not pre-briefed on this product, and I’m not all that thrilled at the prospect of attending a launch webinar, so what you read here is based on my own research and reading of the available information as of this morning.

When EMC announced Project Lightning last year, company insiders expressed surprise to me. It seems that many had never heard of the project, and those that had didn’t think it was far enough along to be announced. I didn’t even bother to write about the Project Lightning announcement at the time. But today EMC unveils the production product that came out of Project Lightning.

VFCache is a filter driver that caches writes

EMC VFCache appears to be a simple and straightforward offering:

1. A PCIe SSD from Micron or LSI sits in the server and acts as a read cache to accelerate performance
2. EMC software also runs on the server, snooping on I/O and filling the cache with relevant data

There’s not a lot more to the product than that. EMC will sell the PCIe SSD and bundled software as VFCache, and will no doubt market the heck out of this product. Perhaps the only novel twist is the so-called “split-card” mode, which allows the card to act as a write cache. But EMC only supports this for transient “throwaway” data with direct attached storage (DAS) as a backend. There’s no way a conservative, enterprise focused company like EMC would risk sanctioning a writeback cache with no redundancy or data protection features.

VFCache uses a filter driver installed in the VM guest

Perhaps the biggest limitation of the initial VFCache offering is its limited applicability to enterprise server virtualization environments. VFCache uses a filter driver installed in each VM guest, and includes no hypervisor drivers though there is a vCenter plug-in. This makes VMware vMotion very tricky, involving scripting to remove and re-add storage. This means VMware SRM will not easily work, and there is no support for clustering, either.

This is no surprise, since VFCache appears to the host as a local storage volume (AKA, a disk drive or LUN) which would disappear if a virtual machine is moved to another server. Virsto solved this problem by virtualizing storage presentation to the hypervisor, and Fusion-io’s ioTurbine software does not interfere with vMotion either. EMC will likely go in this direction in the future, but it’s a big hole in the product for now.

You might also like reading Micron Bursts Into the PCIe SSD Market to learn more about the card EMC is using

The News: EMC Is in the Host-Based Storage Business

The primary use case for this product is server I/O acceleration. This is desperately needed, as applications and servers are rapidly outrunning the capabilities of conventional storage arrays. EMC and other legacy array manufacturers initially tried to address this I/O imbalance with tiered storage and in array caching. Indeed, these technologies are fairly effective at accelerating the performance of conventional disk storage arrays.

But flash manufacturers like Fusion-io (not to mention Micron and LSI) absolutely demolished storage array performance with their in-server offerings. EMC faced the prospect of losing out on the high-performance storage market. EMC simply could not allow their bread-and-butter enterprise customers to look elsewhere for strategic, high-performance storage for high-profile applications.

VFCache gives EMC salespeople a silver bullet when customers demand maximum performance, but this launch may not spell doom for the flash startups. For one thing, it legitimizes host-based flash cards as a viable component of enterprise storage architectures. It also opens the door to comparison between SAN storage and non–SAN alternatives that go well beyond what EMC is currently offering.

Shared Flash Storage Is on Deck: Project Thunder

"Project Thunder" will externalize the PCIe flash cards over a high-performance "Server Area Network"

As part of the VFCache introduction, EMC is also talking about Project Thunder, a shared version of VFCache. At the very least, thunder will allow multiple servers to access a shared pool of flash cache. This should allow VMware vMotion and DRS to function, and could be much more than that.

EMC could build a high-availability, high-performance all-flash storage array that may even use InfiniBand as an interconnect. The new Nimbus Data E-Class storage array matches this description perfectly, and their CEO tells me that performance over InfiniBand is indeed comparable to in-server PCIe flash cards. It seems logical for EMC to enter this market, if only to disrupt the momentum of Fusion-io and the rest of the all-flash storage upstarts.

Read more about the Nimbus E-Class: The First Big, Redundant, All-Flash Enterprise Array

The only fly in the ointment here is the recent consolidation of the InfiniBand market. Mellanox bought Voltaire, and QLogic sold out to Intel, putting that protocol on tenuous grounds. Perhaps 40 or 100 Gb Ethernet will emerge as a viable alternative for high-performance connectivity, or perhaps these products will retrench on shared PCI Express instead. Micron recently purchased Virtensys for just such a product, and Xsigo has been making big waves in the area of converged I/O as well. The market clearly need something better than Fibre Channel for maximum performance storage, even if InfiniBand isn’t it.

Stephen’s Stance

EMC VFCache (née Project Lightning) is a fairly simple offering: A server-based PCIe flash card that acts as a read cache with no integration with storage arrays or hypervisors. But EMC’s entrance into the host-based flash storage market is a powerful demonstration of the wave of disruption caused by flash-based storage and high-performance computing. Although I am not all that impressed with the product itself, I would be distressed if EMC had not introduced it.

VFCache illustrations are copyright EMC Corporation and are used here with permission

More solid, independent VFCache coverage:

• EMC Enters The Market With “Me Too” Flash Products (Chris Evans)
• Cache Splash and Complex is the new Simple (Martin Glassborow)

© sfoskett for Stephen Foskett, Pack Rat, 2012. | EMC VFCache (aka “Project Lightning”) Is One Small Step, But an Important One
This post was categorized as Enterprise storage, Gestalt IT, Virtual Storage. Each of my categories has its own feed if you'd like to filter out or focus on posts like this.

Many enterprise SSD makers are familiar to storage folks like myself, including Hitachi Global Storage Technologies, Imation, Intel, Samsung, Seagate, and Toshiba. Readers of my blog may also recognize Fusion-io, LSI, Micron, OCZ Technology, Texas Memory Systems, and Viridant from my recent coverage, and may have heard of Solid Access Systems, Anobit, Pliant (now part of SanDisk), and others. But some names remain unfamiliar, at least for now. And others, notably Nimbus Data and Violin Memory, are puzzlingly missing from the StorageNewsletter list.

So here’s my rundown of the enterprise SSD makers to keep an eye on in the coming year!

For fun, I am grouping these by how much contact I had with them over the previous year. Although obviously not the most scientific measure of their impact on the storage world, perhaps this will help highlight those that are reaching out to independent bloggers like myself.

Well-Known SSD Players

See also Micron Bursts Into the PCIe SSD Market

First up is a group of companies that I’m quite familiar with, having recently been briefed on their SSD plans and products.

1. LSI
2. Micron
3. Nimbus Data
4. Texas Memory Systems

Next is a list of companies that, although I have contacts of one sort or another, I eagerly anticipate future briefings regarding SSD technology.

1. Anobit
2. Intel
3. Fusion-io
4. Hitachi GST
5. Seagate Technology
6. Stec
7. Violin Memory

SSD Contenders

See also Toshiba Offers “Blade” SSDs (Like Apple’s MacBook Air)

I have spotted the following companies at conferences, in industry publications, and on the web and feel that I am somewhat familiar with their SSD plans. But I welcome any opportunity to get to know them better, and encourage them to contact me via e-mail or by telephone.

1. OCZ Technology
2. Imation
3. Samsung
4. SanDisk / Pliant Technology
5. Solid Access
6. Toshiba
7. Viking Modular Solutions
8. Virident Systems

Who?!?

I was surprised to see this set of companies listed in the StorageNewsletter article, and more surprised when I went to their website and found that they were working on genuine and interesting enterprise SSD products. I would love to get in contact with folks at these companies so I can learn more about what they are up to!

1. BiTMICRO Networks
2. Foremay
3. Macrotron Systems
4. pureSilicon
5. RunCore
6. Smart Modular Technologies
7. Super Talent

Stephen’s Stance

In all, I located 25 companies that build solid-state storage devices for the enterprise market. My quick examination of their websites (or previous knowledge of the companies) reveals a wonderful and vibrant culture of innovation around solid-state storage technology. Watch this space over the next year, since I intend to cover the SSD space in detail!

I would like to thank Jean-Jacques Maleval for spurring my research into these enterprise SSD companies. He is really doing a great job over at StorageNewsletter, and I recommend that you subscribe!

© sfoskett for Stephen Foskett, Pack Rat, 2011. | My Incomplete, Subjective List of Enterprise SSD Companies
This post was categorized as Enterprise storage, Personal, Virtual Storage. Each of my categories has its own feed if you'd like to filter out or focus on posts like this.

VMware's PSA is awash in abbreviations and options

I am often questioned during my Storage for Virtual Environments seminar presentations about VMware’s Pluggable Storage Architecture (PSA). This system is fairly straightforward and concept: VMware provides native multipathing support for a variety of storage arrays, and allows third parties to substitute their own plug-ins at various points in the stack. But the profusion of acronyms and third-party options makes it difficult for end-users to figure out what is going on. In an effort to help, I present here another entry in my “VMware storage features in plain English” series.

Note: I am more of a storage guy than a virtualization expert. I consider myself one of those end-users who have had trouble figuring out what’s going on with PSA specifically, in VMware storage features in general. I welcome comments and suggestions for corrections or improvements to this and all of my articles. Thanks for your help!

Introducing Pluggable Storage Architecture (PSA)

Pluggable storage architecture was one of the major enhancements introduced in vSphere 4. Functionally similar to Microsoft’s MPIO stack for Windows, PSA includes native multipathing support and allows vendors to plug in their own advanced features.

I find the VMware diagram confusing. Is mine more or less accurate and readable?

The ESX kernel (VMkernel) walks down through three layers when communicating with storage:

1. In the top layer, VMware native NMP or third-party MPP software decides which SATP to use, or whether to use the native interface. MASK_PATH also operates at this layer.
2. The SATP layer includes native generic path selection (active/active, active/passive), standard ALUA, as well as allowing third-party plugins (SATP) to override its behavior. The SATP monitors these paths, reports changes, and initiates fail-over on the array as needed.
3. At the PSP layer, software decides which physical channel to use for I/O requests.

There are three types of PSA plugins for vSphere 4:

1. Storage Array Type Plug-In (SATP)
2. Path Selection Plug-in (PSP)
3. A complete third-party multipathing software stack (MPP)

As is the case with VAAI, VMware includes a number of third-party plug-ins in the ESXi install. Users can simply activate many of these according to their needs, though some require additional fees and licensing.

Storage Array Type Plug-in (SATP) List

Storage Array Type Plug-Ins (SATPs) to the VMware Pluggable Storage Architecture multipathing solution for the specific characteristics of the storage array. This is very important, since each storage array design differs substantially in detail and support, especially when it comes to load-balancing and failover between controllers, ports, and paths. So it is critical for VMware to have developed a standard interface to communicate with arrays.

SATPs allow load balancing across multiple paths, intelligent path selection, and over troubled conditions such as “chatter”, when passed rapidly fail back and forth between controllers.

The SATP has critical tasks to perform in the PSA stack:

1. Decide which method of communication to use with the storage (PSA or native)
2. Monitor the health of the physical I/O channels or paths
3. Report any changes in the state of the paths up the stack
4. Perform actions required to fail over storage between controllers on the array

VMware vSphere includes a variety of generic plugins for storage arrays. I’ve identified the following:

• VMW_SATP_LOCAL – Local SATP for direct-attached devices
• VMW_SATP_DEFAULT_AA – Generic for active/active arrays
• VMW_SATP_DEFAULT_AP – Generic for active/passive arrays
• VMW_SATP_ALUA – Asymmetric Logical Unit Access-compliant arrays

Although I have sometimes seen other SATP plug-ins mentioned, the following plug-ins are all that are listed in the VMware ESX Hardware Compatibility List.

• VMW_SATP_LSI – LSI/NetApp arrays from Dell, HDS, IBM, Oracle, SGI
• VMW_SATP_SVC – IBM SVC-based systems (SVC, V7000, Actifio)
• VMW_SATP_CX – EMC/Dell CLARiiON  and Celerra (also VMW_SATP_ALUA_CX)
• VMW_SATP_SYMM – EMC Symmetrix DMX-3/DMX-4/VMAX, Invista
• VMW_SATP_INV – EMC Invista and VPLEX
• VMW_SATP_EQL – Dell EqualLogic systems

EMC PowerPath and HDS HDLM also support a variety of storage arrays, but I would classify these as full MPP replacements for PSA, rather than SATP plug-ins.

You can see which SATP plug-ins are available using the following esxcli command:

esxcli nmp satp list

Path selection plug-in (PSP) List

In contrast to the diversity of VAAI and SATP plug-ins, the universe of path selection plug-ins is fairly small. Most storage arrays are supported with either Most Recently Used (MRU) or Fixed path selection approaches. Many also support Round Robin (RR) path selection. The only vendor with a specific PSP that is not also part of a full MPP (like EMC PowerPath or HDS HDLM) is Dell, which offers a special routed path selection plug-in for the EqualLogic iSCSI arrays.

• VMW_PSP_MRU – Most-Recently Used (MRU) – Supports hundreds of storage arrays
• VMW_PSP_FIXED – Fixed – Supports hundreds of storage arrays
• VMW_PSP_RR – Round-Robin – Supports dozens of storage arrays
• DELL_PSP_EQL_ROUTED – Dell EqualLogic iSCSI arrays

As mentioned, EMC PowerPath also offers path selection as a plug-in in addition to the full MPP stack. Many other vendors offer unique path selection plug-ins, over 100 in total, but these are not specifically called out in the VMware HCL apart from their existence. I would love to learn more about them, however.

You can see which SATP plug-ins are available using the following esxcli command:

esxcli nmp psp list

Tell Me More About PSA!

As mentioned above, I am by no means an expert in VMware Pluggable Storage Architecture. Rather, I am interested in learning more and passing on this knowledge to others. I welcome your comments and feedback, and especially your corrections to the information presented here. I will try to keep this page updated as new versions of vSphere are introduced and as I learn more about this technology. Thank you for your help and understanding!

Further Reading:

• What’s New in VMware vSphere 4: Storage
• Next-Generation ESX Storage: A Pluggable Core Storage Architecture
• Storage Changes in the VMware vSphere 4 Family
• Pluggable Storage Architecture, exploring the next version of ESX/vCenter
• Vmware vSphere 4.1 PSA (Pluggable Storage Architecture) Understanding
• Explain the Pluggable Storage Architecture (PSA) Layout

© sfoskett for Stephen Foskett, Pack Rat, 2011. | VMware PSP and SATP in Plain English
This post was categorized as Enterprise storage, Everything, Virtual Storage. Each of my categories has its own feed if you'd like to filter out or focus on posts like this.

The Micron RealSSD P320h is more than a new form-factor for the company; it also introduces their RAIN technology

This morning, Micron announced their “RealSSD” P320h SSD, bringing them into the PCIe storage market for the first time. Already a leading supplier of both consumer and enterprise SATA SSDs, as well as the world’s leading supplier of NAND flash in partnership with Intel, this move puts Micron in direct competition with existing suppliers like media darling Fusion IO.

Introducing the RealSSD P320h

The RealSSD P320h SSD can be seen as a PCIe companion to the existing P300 series of enterprise SSDs, but it is much more than that. Micron brands their entire SSD line “RealSSD”, from the consumer grade C300 and C400 (which Crucial sells as the M4) to the enterprise P300. All include Micron’s own SSD controller ASICs and flash memory modules, offering greater levels of integration and profitability for the company.

The P320h seems similar to the recently introduced P300 in terms of componentry, but the PCIe interface puts it into a different realm of performance. Although Micron’s RealSSD line is lauded for its 6 Gb SATA interface, an internal PCI express card like that P320h blows the doors off any disk interface. Micron’s presentations show the P320h delivering over many times the IOPS of their already speedy P300! As demonstrated already by numerous competitors, there is no substitute to the low latency I/O performance of a PCIe card.

The RealSSD P320h will initially be offered in two models, both in the full-height half-length PCIe form factor. The 350 GB model offers slightly lower random write performance than its 700 GB big brother, but both boast massive performance numbers. Both use 34 nm SLC flash chips and are built on a 32-channel design.

Massive Performance

The P320h delivers astonishing performance, at least in Micron’s PowerPoint illustrations. My own C300 can push 250 MB per second of sequential writes, and the enterprise class P300 is maybe a bit faster. But the P320h is rated at 2 GB per second sustained sequential write performance, nearly an order of magnitude faster. It would be difficult find an application, let alone a server, that could sustain this kind of throughput for long.

Micron boasts industry-beating throughput

Even more important than throughput is I/O performance. SSDs like my C300 excel at servicing I/O requests, and are rated at 30,000 to 45,000 random 4K write IOPS. Again, the P300 is able to match this level of performance while providing five-year reliability for enterprise applications. But the P320h delivers nearly 350,000 4K write IOPS, besting the fastest and most expensive enterprise storage arrays in existence.

Micron's IOPS claims are astonishing

Note that all numbers in these charts are from the manufacturers’ own specification sheets: Micron P320h, Fusion I/O ioDRIVE DUO, TMS RamSan-70, LSI WarpDrive SLP-300, OCZ Z-Drive R2 e88, Virident tachIOn. I have included two of Micron’s RealSSD SATA drives for comparison purposes: Micron P300, Micron/Crucial C300.

Benchmarks should always be taken with a grain of salt, and manufacturer spec-sheet claims are doubly dubious. But Micron makes these claims, and it won’t be long before these devices are independently benchmarked.

Digging Deeper Into the Hardware: RAIN Reliability

The P320h is a first for Micron in a number of ways. Along with being their first PCIe card, it also is the first SSD to feature Micron’s so-called RAIN architecture and RealSSD Manager software. The P320h includes optimized drivers for Windows and Linux to further improve performance, but Micron is leaving it to partners to integrate the SSD with operating systems, hypervisors, or applications.

RAIN is Micron’s answer to concerns about SSD reliability in the enterprise. Although already using ultra-reliable SLC chips, the P320h introduces a raid like technology Micron calls Redundant Array of Independent NAND, or RAIN for short. Reminiscent of SandForce’s Redundant Array of Independent Silicon Elements (RAISE), RAIN arranges flash memory chips in a 7+1 arrangement to improve reliability and recoverability in the event of a failure.

Micron claims that this combination of intelligent controllers, RAIN, and SLC memory chips delivers top-notch reliability. The company measures reliability in terms of the number of full drive fills that can be sustained per day for five years. They claim that enterprise customers demand SSDs that can sustain 30 fills per day for five years, or an incredible 54,750 drive fills. That’s 25 PB of data written for 350 gig unit or 50 PB for the big 750 GB P320h!

Putting things another way, if the 700 GB P320h was pounded with sequential data at its rated maximum of 2 GB per second, it would take over nine months to wear out this drive. Just in case the customer expects to hammer on the drive constantly, they may use the RealSSD Manager software to throttle performance and ensure reliability to a given date.

Stephen’s Stance

PCIe SSDs like Micron’s new P320h offer mindbending performance and enterprise class reliability. Although expensive, these devices are in an entirely different league from any other storage option. Micron promises to bring the PCIe P320h to market at nearly $15 per gigabyte, a substantial discount over other PCIe SSD competitors. But the card will still cost more than $5000, making it an expensive add-on for most servers.

The challenge in enterprise storage is not delivering absolute capacity or performance any longer. Today’s challenge is making that capacity and performance available to applications and, ultimately, and users in the form of improved satisfaction or profitability. Micron is moving the ball forward on the hardware front, but my focus remains on software providers that will deliver this performance in a usable form for applications, hypervisors, and operating systems.

And what’s next from Micron? I expect a SAS HDD-form factor SSD shortly, and perhaps a line of PCI Express Mini Cards or “Blade” SSDs might follow.

© sfoskett for Stephen Foskett, Pack Rat, 2011. | Micron Bursts Into the PCIe SSD Market
This post was categorized as Enterprise storage, Gestalt IT, Virtual Storage. Each of my categories has its own feed if you'd like to filter out or focus on posts like this.

HP invited bloggers to Colorado to show off their storage offerings at Tech Day 2009

Well that was interesting! I spent Monday and Tuesday with a dozen bloggers in Colorado Springs learning about HP’s key StorageWorks products from the executives and engineers of that storied company. Throughout the event, we listened, asked tough questions, and tweeted incessantly. HP Tech Day generated an avalanche of publicity for the company, including press articles and cries of FUD and misdirection.

Here is the truth: HP and Ivy did a darn fine job of putting together a set of sessions to tell us what they have. They presented folks who really knew their stuff, warts and all. They invited a variety of independent voices and let us ask and say anything we wanted with no expectations, let alone an NDA. This was a stellar event, and every other IT company should be asking why they didn’t do it first.

Won’t Be Fooled

But what was HP Tech Day really all about? Did they brainwash us into thinking the EVA was exciting? Did HP hoodwink and misdirect us from noticing the gaps and overlaps in their product line? Were we dazzled enough to no longer question their storage strategy? Of course not! Robin Harris has seen it all before. Rich Brambley can dissect a presentation with the best of them. Nigel Poulton questions everything he sees. This was not a love-fest, and there were some seriously uncomfortable moments for the HP crew.

We were all savvy enough to know what the score was: HP (and especially their StorageWorks product line) has never received much press or blogger attention. They invited us in to spread the word about their products and get blog exposure. And it worked! The storage Twitter-sphere was dominated with #HPTechDay postings for days, and attendees did indeed blog about the stuff they saw. It was a success from HP’s perspective, and now that we know more about their products we will likely cover them in the future.

I personally never blogged much about HP products. I compared them to Ford, called one product an all-time cool flop, and covered their acquisition of LeftHand and Ibrix, but that’s about it. I didn’t even notice that they had started selling LSI’s StoreAge-based virtualization platform, and didn’t know enough about their other product releases over the last two years to mention them. If it hadn’t been for Calvin Zito and the HP Tech Day, I probably wouldn’t mention them in the future, either. They just weren’t on my radar.

We Were Educated

This has changed as a result of Tech Day. I now know that EVA is still pretty much what I thought it was but that it is fairly simple to configure. I now know that HP has two lines of deduplication appliances, and that one is homegrown. I now know that HP develops and sells a FC SAN virtualization platform based on the LSI/StoreAge product. This was great product exposure for HP: Even though I still don’t think I’ll focus on these offerings, at least I now know that they exist.

We also saw some more interesting content: HP plans to leverage their excellent ProLiant server and blade technology to underpin a line of commodity-based storage and consolidated virtualization offerings. This is exciting stuff, and builds on HP’s base and their recent acquisitions. The most interesting concept I saw was a combination of a blade chassis and ultra-dense storage system with VMware ESX, LeftHand, Ibrix, and HP’s management software. They definitely plan to challenge Cisco/EMC and IBM in this market.

But the best part of the event was the people of HP. The company was smart enough to bring in the techies rather than executive marketing droids. They gave us straight and honest answers about their product capabilities and their place within the company, sometimes to the chagrin of others in the room. We saw conflicting definitions, product line overlaps, internal competition, and got a feel for the realities of this massive company. Every company is like this, but most would never admit what we already know. By not showering us with slick FUD, HP won our respect in a way that I would not have thought possible.

Colorado Take-Away

The event was great. Every other IT company should wise up and do the same. But I bet they won’t have the nerve to do it as openly, and I expect HP will be more careful next time too. As for HP’s products, let me lay out my honest opinion:

1. LeftHand was a bargain. HP could replace their entire sub-XP block storage product line with LeftHand variants based on commodity Intel hardware. I think they should.
2. Ibrix is too new to judge, but will likely take a seat next to LeftHand in a unified commodity-based scale-out SAN/NAS platform.
3. I hope HP hasn’t lost focus on their excellent Hitachi-based XP line, since it’s the only challenger they have to EMC Symmetrix at the high end of the market.
4. HP’s excellent server and blade hardware should be leveraged throughout the company and oddball hardware should be curtailed.
5. HP has an interesting lineup of Windows Storage Server and Windows Home Server hardware aimed at the low-end SOHO and SMB market. I’m not a Windows hater, but wouldn’t it be cool to have a super-low-end LeftHand variant there too?
6. I wonder if HP’s home-grown in-line deduplication (the D2D line) could replace the Sepaton-sourced post-process VLS line or vice-versa if an acquisition of that company happens.
7. I don’t “get” SVSP, the LSI/StoreAge SAN virtualization platform. It’s nice and it seems to work, but why introduce a FC SAN virtualization platform at this point? Maybe it sells when integrated with EVA, but not as a standalone product.
8. Where are all the storage arrays that use 2.5″ disk drives that HP talked about over the last few years? And where are the flash solid state drives?
9. They were like deer in the headlights with no story when I asked about sub-LUN automated tiered storage since even full-LUN automation has not yet been released. Might EMC get there first?
10. As for the absence of DCB and FCoE, HP seems to think that Virtual Connect and Flex-10 are good enough for now. HP will OEM a CNA soon and might possibly consider the Cisco Nexus 4000. Maybe. They had better have a more-convincing story when this stuff takes off next year!
11. Most importantly, where is the cloud strategy? I applaud HP for not overusing the current buzzword, but it almost seems like they are avoiding the topic entirely.

I am left thinking that HP is like a boxed puzzle. All of the pieces are there, but they haven’t been put into place yet. Let’s hope Dave Donatelli and his crew can help them work it out when he takes his post as czar of servers, networking, and storage next year. For now, I’ve gained a lot of respect for the people of HP and a pile of knowledge about their storage products. And HP has gained my attention.

© sfoskett for Stephen Foskett, Pack Rat, 2009. | The Truth About HP’s Tech Day
This post was categorized as Enterprise storage, Everything, Gestalt IT, Personal, Virtual Storage. Each of my categories has its own feed if you'd like to filter out or focus on posts like this.

For more information on earlier updates, see my articles:

• Storage Fixes in VMware ESX Server 3.5 Update 2
• Storage Changes in VMware ESX 3.5 Update 3

Expanded Support for Enhanced vmxnet Adapter

Not specifically a storage change, but the enhanced vmxnet adapter introduced back in the original release of ESX 3.5 now works with most versions of Windows Server 2003 and XP Pro. Look for improved performance when using guest-side SMB and NFS as well as the guest iSCSI initiator. Note that you cannot select this driver when configuring non-Enterprise Edition machines; you have to select Windows Server 2003 Enterprise Edition (64-bit) regardless of which version of Server 2003 you are using.

Expanded SAS and SATA Controller Support

If you’d like to install ESX on a server equipped with a PMC 8011, Intel ICH9 or ICH10, CERC 6/I SATA/SAS Integrated RAID Controller, or HP Smart Array P700m Controller, you’ll find happiness in Update 4.

The Intel controllers are especially important, as we’re seeing them used more and more and this driver is more full-featured than the earlier Broadcom HT 1000 and Intel ICH7 drivers. The Intel ICH9/ICH10 is a dual-mode (IDE/ATA and AHCI/SATA) driver, supports SATA hard drives, SSDs, and optical drives, and now enables VMFS support when in AHCI/SATA mode. It’s not clear whether VMware actually supports VMFS datastores on ICH9/10 SATA, but it says it works. Anyone want to try it out? One thing is certain: You can’t use SATA drives in a shared/clustered environment because SATA does not include reservations. See this tech note and especially this question:

Earlier, it was mentioned that we can create VMFS if we use AHCI/SATA mode. If so, why did VMware not claim VMFS support when using SATA controller running in AHCI/SATA mode?

VMware might decide to add support in the near future. There is no strong need to have VMFS support on a SATA drive, because native SATA protocol does not support reserve/release. Reserve/release is needed if VMFS is used as clustered file system in a shared disk environment.

PXE Boot Support

Rich at VM/ETC points out that Update 4 includes experimental PXE boot support for ESX and ESXi. As he notes, this has major implications for cloud computing platforms, since it means that ESX servers can boot guests without local storage at all. Very interesting! Let’s bet that Update 5 (expected in June or July) will include this as a supported option.

Updated QLogic, Emulex, and LSI Drivers

Like most ESX updates, this one included updated Fibre Channel drivers.

• The QLogic Fibre Channel Adapter driver and firmware (versions 7.08-vm66 and 4.04.06, respectively) include bug fixes and enhanced NPIV support.
• On the Emulex side, driver version 7.4.0.40 supports the company’s HBAnyware 4.0 management software.
• Users of SAS and SCSI LSI MegaRAIDs will find driver version 3.19vmw (megaraid_sas) and 2.6.48.18 vmw (mptscsi) which improves performance and enhances event handling capabilities.

Expanded Sun Storage Array Support

All you StorageTek loyalists out there will be happy to see support for Sun’s low-end StorageTek 2530 SAS array as well as the modular 6580 and 6780 Fibre Channel arrays. It looks like just about every model in Sun’s current storage lineup is now supported in ESX.

Expanded Network Card Support

Support for Gigabit cards is greatly expanded, including HP’s quad-port NC375i and dual-port NC362i and NC360m, Intel’s Gigabit CT and 82574L, and NetXtreme’s BCM5722, BCM5755, BCM5755M, and BCM5756. Intel’s widely-used 10-gig 82598EB cards are now supported as well.

Tweaks and Fixes

Looking through the release notes, a few storage-related tweaks and fixes stand out:

1. WMware can optionally automatically throttle back the queue depth when congestion is encountered. See Controlling LUN queue depth throttling in VMware ESX for 3PAR Storage Arrays for more information.
2. VMklinux module heap size can now be adjusted as LUN queue-depth values are increased. Since tuning LUN queue depths is one common trick of the storage trade to improve performance, especially in queue-stingy systems like ESX, this is welcome news. But call VMware support before you monkey with it!
3. An RDM-related issue where SCSI inquiry data over 36 bytes was truncated or corrupted (for example when using Microsoft VSS and NetApp SnapDrive) has been resolved.

Well, that’s all folks. I suggest you all read the release notes for yourself, and please leave a comment if you see an error in what I wrote here or have something to add!

© sfoskett for Stephen Foskett, Pack Rat, 2009. | Storage Changes in VMware ESX 3.5 Update 4
This post was categorized as Enterprise storage, Gestalt IT, Virtual Storage. Each of my categories has its own feed if you'd like to filter out or focus on posts like this.

The Register did a nice job of summing up the (late 2008) flash positioning of the various storage companies, and I recently posted a strategic look at this core issue. Note that some, like HP and Sun (and probably IBM), seem to have an end-to-end strategy, while others are firmly in one camp or the other. In the “not yet” column, apparently, are 3PAR, BlueArc (though they offer TMS RAM), Dell/EqualLogic, HP/LeftHand.

Update: 3PAR has joined the “disk” camp.

It’s a Cache

Fusion-IO has rocketed to the forefront of the cache side with their PCI Express flash boards for servers. Joining them in this position are the following companies:

• HP (blades and servers)
• NetApp (PAM read cache card)
• Pillar (Slammer cache)
• Sun (read and write cache)

It’s a Disk

STEC is the darling of the flash-as-a-disk world, though Intel, Marvell, and Samsung are also playing here. Joining them in the corner are the following:

• EMC (STEC flash drives shipping the DMX now and CLARiiON in the future)
• Compellent (flash drives)
• HDS (flash drives in the USP-V)
• HP (flash drives in the MSA, perhaps, and maybe that Oracle thing)
• IBM (Fusion-IO storage behind SVC and standard flash drives in the DS5000)
• LSI (flash drives in the 7900)
• NetApp (ssd drives)
• Pillar (flash drives)
• Sun (flash drives in Thumper and JBOD)
• Xiotech (flash drives in the next Emprise canisters)
• 3PAR (flash drives in InServe)

So there you have it. It’s both a disk and a cache, depending on whether you sell servers or arrays apparently. If you sell both, it’s both. Simple!

If anyone wants to correct any of this, drop me a line or comment below!

See my posts on Gestalt IT for similar enterprise IT infrastructure commentary

© sfoskett for Stephen Foskett, Pack Rat, 2008. | Is Flash A Disk Or A Cache?
This post was categorized as Enterprise storage, Virtual Storage. Each of my categories has its own feed if you'd like to filter out or focus on posts like this.

So what’s IBM doing this time? Well, they’ve taken LSI’s proven Engenio 1333 array technology (which they’ve used for a while) and turned on iSCSI functionality. IBM veers off course from the startups by not bundling snapshot and replication technology with their new array, however. This reduces the cost of entry but diminishes the impact of this new technology, since adding that software can easily double the price of this Ford Escort storage system.

IBM has also certified a complete Fibre Channel SAN solution with Microsoft, if you’re into that sort of thing. Their DS3400 can chat with an Emulex HBA and Brocade switch with quick setup and guaranteed compatability or your money back! (I made up that last part…) I’ve been pleased by Microsoft’s Simple SAN push in the past and think this is an excellent alternative to iSCSI for sites that aren’t ready to take the storage-over-Ethernet plunge yet.

Why care? Well, simply because this “compact” market is where the big action is in storage right now. Thanks to the VMware explosion, just about every smaller-than-10-TB shop is currently buying and deploying SANs right now, a fact that has warmed the hearts (and fed the sales people) at companies like EqualLogic, LeftHand, HP, Dell, and the rest for a year or so now. IBM was too early to market with an iSCSI array back in 2001, but has had nothing to sell since they axed the Adaptec-powered DS300/400 back in January. Welcome back!

© sfoskett for Stephen Foskett, Pack Rat, 2007. | IBM Warms to the Compact Storage Market
This post was categorized as Enterprise storage. Each of my categories has its own feed if you'd like to filter out or focus on posts like this.

Now a handful of storage players are talking about SSD’s again, including some respectable names like LSI and Xiotech and some lesser-known outfits like Solid Data Systems and Texas Memory Systems. IDC is predicting mainstream uptake of the technology, too, but note that they’re mostly talking about the PC market, not enterprise storage.

I say that if SSD ever gains footing in the enterprise, it’ll most likely be in a virtualized hybrid system, acting like a mega-cache. Or maybe a non-RAM permacache, if you will! Of course, we’ve seen just how much uptake that feature has had, eh EMC? But hey, it could happen. Even though Apple is soaking up more than a quarter of the world’s NAND flash this year, maybe they’ll force prices down. Or maybe Samsung’s or Hynix’s PRAM will conquer the world!

Let’s get serious, folks. What good is SSD? It improves random access read performance over disk at the expense of longevity, throughput, and, well, expense! ReadyBoost looked like a nice application for flash memory, since the potential content was bounded and could fit on a flash drive, but it seems to have done precisely nothing for performance.

If enterprise applications could benefit from better random access performance, we’d be putting large amounts of memory in front of the disks already. Oh, wait, that’s right, we already do that! Modern enterprise arrays have gobs of cache, more than any SSD, and use it quite effectively. Remember the old RAID-5 penalty?

SSD just serves to remind me of one of those performance-tuning axioms I learned long ago: It’s always better to let an intelligently-designed system manage itself than try to second-guess it. This applies to all areas of system performance tuning, from filesystem and LUN layouts to cache tuning. And this is why permacache and things like it never caught on.

And it’s why SSD will continue to play just a bit part in the enterprise until it’s just as cheap as disk. Like that’ll happen anytime soon.

Edit: Looks like I got the name wrong – the EMC SSD was the Orion.  Introduced in 1989, this evolved into the Symmetrix in 1992.  I used one of these back at Texaco in the 1990′s.

© sfoskett for Stephen Foskett, Pack Rat, 2007. | Wherefore Art Thou, Solid State Disks?
This post was categorized as Apple, Computer History, Enterprise storage. Each of my categories has its own feed if you'd like to filter out or focus on posts like this.