Stephen Foskett, Pack Rat

As I mentioned on Monday, VMware’s Update 2 for ESX 3.5 includes support for 8 Gb Fibre Channel HBAs. This is an important development, so I went looking through the official ESX I/O Compatibility Guide to see which HBAs in particular were supported, but none were listed.

This was pretty puzzling, but Rich from VM /ETC and Duncan from Yellow Bricks were right - they just hadn’t updated the guide yet (even though the revision date was July 25).

So without further ado, the announcement:  You can now use Emulex and QLogic 8 Gb Fibre Channel HBAs with VMware ESX to give blazing I/O performance right where it’s needed.  Of course, 8 Gb storage arrays remain rare, but this will change soon.

An end-to-end 8 Gb FC SAN will likely provide all the performance of 10 Gb FCoE, and it’s available now instead of 2009 or 2010.  10 Gb iSCSI and NFS are also supported as of Update 2 if you’re more of a TCP/IP person…

VMware just released Update 2 for VMware ESX Server 3.5 (Virtual Infrastructure), and it includes some storage fixes of note:

1. Support for Volume Shadow Copy Service (VSS) for filesystems Windows Server 2003 and Windows Server 2008 guests.  This means VMware services like VCB and SRM can now signal Windows Server to quiesce filesystems before creating a clone or snapshot and is a major addition!
2. Windows Server 2003 guests also get application quiescing, where supported.
3. You can now extend a live, running VMFS volume as storage is added, just like Windows Vista and 2008 guests could already do with raw device mode (RDM).  Note that this only works for flat disks with no persistent snapshots open.

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I had two great storage virtualization seminars this week, in New York and Philadelphia.  As usual, audience participation was key, and interest in VMware and Hyper-V remains high.

One of the main questions I always get is which protocol one should use for VMware storage. My recommendation remains that the answer is an organizational one more than a technical one.  There are certainly performance, CPU utilization, and support differences between Fibre Channel, SCSI, iSCSI, and NFS on VMware, all of these can work fine in many situations.  Although this is addressed in my presentation, I thought it wise to point out some of my sources and (concurring) opinions.

First, I point you to the official VMware VI Team blog, where they reiterate that VMware is protocol-agnostic.  They commit to support all storage protocols equally, and promise to add missing support as soon as possible.  See especially their table of support, which shows that iSCSI currently can’t be used for clustering (!), among other insights.

I’d also like to point out three sources for my seminar slides:

• VMware’s Comparison of Storage Protocol Performance paper, which pits Fibre Channel against hardware iSCSI, software iSCSI, and NFS.
• VMware’s Performance Characterization of VMFS and RDM Using a SAN, which shows that there is a negligible performance difference between shared storage and the two varieties of RDM.
• NetApp’s NetApp and VMware Virtual Infrastructure 3 Storage Best Practices (recently updated), which is a wealth of information on shared storage with NFS, even if you’re not a NetApp customer.

TechTarget recently uploaded three podcast versions of my SAN School series from Storage Decisions last year.  These are audio-only, but I might be able to dig up the accompanying slides.  If you’re interested in this, please leave a note below or contact me through email.

So without further ado, I present three lessons on SAN storage:

• SAN School Lesson One: Building a SAN - In this first lesson of SAN School, I discuss the different types of storage arrays, switches, and software that make up a storage network.
• SAN School Lesson Two: SAN Architecture and Topology - In lesson two, I discuss the evolution of SANs from standalone entities, to islands and beyond. Discover techniques that can make a substantial difference in the way data is moved and processed, as well as in your company’s consolidation plans.
• SAN School Lesson Three: SAN Management and Security - In this Podcast, I explain what the options are for management tools. I cover array management, change management, virtualization and more to help you manage your environment. 

Real Video: Where the SAN Stands

Curious about the current state of SAN technology?  Stephen Bigelow of TechTarget interviewed me (last summer) about SAN options, and the video is now live on their BitPipe site.

Topics covered include combined iSCSI and FC SANs, ups and downs of modular storage and oversubscribed switches, next-generation SAN management applications, storage virtualization, and best practices for SAN design.

Here’s a snip - the three best practices for SAN design are as follows:

1. Choose reliable high-quality hardware
2. Build dual redundant networks
3. Protect management interfaces

Watch the whole video (it’s 17 minutes long) and let me know what you think!

 

Fibre Channel over Ethernet (FCoE) has been a hot topic of discussion in the enterprise storage world lately, but many end users are just now hearing about it.  Although some folks seem to think it’s here with a vengance, others doubt that it will ever make the splash it promises, with 8 Gb FC, iSCSI, and even AoE (ATA over Ethernet) showing more promise.  There has been some back and forth, and even a little backpedaling.

What do you think?  If you’re a Plaxo user, I created a poll over there to see if folks think it will rise, and when.

Imagine there was someone many people loved to hate, but grudgingly loved just the same because of their incredible prowess. In Red Sox Nation, that would be Alex Rodriguez, who we follow year after year with a mix of admiration, envy, and anger as he seems to make all the right moves for the wrong team. Lots of IT people feel the same about Microsoft, whose runaway success is only slightly tempered by occasional schadenfreude when a misstep is made. In our little corner of the world, storage pros have even more reason to wonder how Microsoft can continue to make good move after good move.

It wasn’t always like this - be thankful if you don’t remember FTEDIT! But ever since Windows 2000, Redmond has made improvement after improvement, remaking “bad (SAN) citizen” Windows into Martha Stewart. But unlike the latter, Microsoft hasn’t called much attention to its skills, and this is a shame…

Take iSCSI - Microsoft was an early supporter of the protocol, releasing an excellent software iSCSI driver as a free download. They also bundle a limited (but continuously-improving) volume manager with all modern versions of Windows. Then there’s VSS, which is the first hardware-independent (even hardware-free!) snapshot API I know of. I’ve written articles (1, 2) on Windows storage technologies which go into these in more detail.

But one question that came up in my virtualization seminar made me realize that I forgot one key piece of Gates-tech: MPIO. See, Microsoft has also been bundling a free hardware-independent multipath I/O driver in server editions of Windows since 2003, but lots of folks haven’t gotten the memo. It’s good stuff: A generic driver with device-specific modules (DSMs) for different storage array and network types. MPIO handles transparent multi-path failover (for availability) and load balancing (for performance).

If you have iSCSI, you simply must try MPIO since Microsoft’s own free DSM supports about everything you need, and compatibility is required for logo support. And if you’re on Fibre Channel, you’re probably in luck, too, since most major vendors provide DSMs for their arrays (but some might not be free, I’m told).

So there you have it. Another excellent (and free!) Microsoft product that you (probably) never heard of, cutting out proprietary solutions (at least for Windows Server…)

One of the hits from my TechTarget storage virtualization seminar this week was a discussion of the relative merits of different storage protocols. Sounds deadly, but this can be quite a religious issue for folks, and it generated lively debate. I’m firmly in the “do what works” camp - there is no always-right protocol, and they all can work.

In the interests of all, I’d like to point out two delicious sources of VMware storage protocol wisdom:

An internal paper from VMware’s performance folks titled Comparison of Storage Protocol Performance shows that, as expected, Fibre Channel has the lowest CPU overhead and best overall throughput. But, no surprise to anyone who’s tested alternatives, iSCSI and NFS also work pretty darn well! And you can knock that extra CPU load right down to the FC level with an iSCSI HBA.

Next up is a best practices paper from Network Appliance that is chock full of VMware storage goodness. If you’re curious about the potentials of NFS storage for VMDKs, this paper is a must-read! I’m pretty impressed with what VMware over NFS has to offer.

By the way, my next seminars are June 24 and 26 in Atlanta and San Francisco, respectively. I’ll also be presenting some related content at Storage Decisions in Chicago in May and Toronto in June.

Update:  Marc Farley talks back - isolate your networks, people!

Another week, another excellent TechTarget tech tutorial by my buddy, Stephen Bigelow. This time it’s on iSCSI and Fibre Channel Integration, and once again that Stephen Foskett guy is quoted. What a smarty-pants!Â

With yesterday’s release of both an iSCSI version of it’s entry-level DS3300 and a complete, Microsoft Simple SAN-certified DS3400 solution, IBM is bringing the love to the … umm … well … compact (?) end of the storage market. See, we can’t call it “low-end” because these devices are decidedly not “low-end” in their functionality. And we can’t call it “entry-level” or “small business” because lots of established players buy this stuff. Modular and monolithic may describe some hardware, but it hardly differentiates the market. I refuse to start with tall like Starbucks (though you can get a super-tasty short cappuccino there!) So let’s just ape the car market and call it “compact”. There’s no shame in owning a compact car, especially with gas prices where they are, so why not get some compact storage to go with your green data center?

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!