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.

I am not the typical enterprise storage user. In fact, I am not an enterprise storage user at all – I am a consultant focused for over a decade on assisting enterprises with their storage architecture and strategy, working with businesses of all sizes. My background is both a blessing and a curse – I have seen far more enterprise storage environments in much more detail than most people, but I am unable to truly empathize with my corporate storage compatriots since it’s not really my gear and data that I am working with.

Based on this experience, what does the future hold? Where is enterprise storage heading? Read on for my thoughts.

Fibre Channel

Although the commoditizing storage market would seem ripe for stagnation, the opposite is happening. In fact, the enterprise storage market has continued to diversify, with iSCSI recently expanding the options for storage connectivity to a new market and FC seeing rapid uptake in the virtual server arena. Fibre Channel over Ethernet (FCoE), whether or not part of the datacenter Ethernet push, is joining virtualized I/O technology based on InfiniBand as the next wave in connectivity. Simply put, the market is not standing still.

Focus on the new world of storage area network (SAN) connectivity can take away from the basics, however. Traditional switched Fibre Channel (FC) remains the healthy market leader, and the recent upgrade to 8 Gb speed has attracted customer attention. Although they are unlikely to run out and perform a mass upgrade, 8 Gb FC is as as much of an inevitability as 4 and 2 Gb before it. The switch will be made, and customers will upgrade organically.

One of the big beneficiaries of 8 Gb FC will be those with virtual servers. This new hardware is coming just as N_Port ID virtualization (NPIV) is maturing, and this technology, which enables multiple servers to share a single FC interface, in combination with a doubling of bandwidth will make modern Fibre Channel tech extremely attractive to virtual server shops.

Even those who do not adopt 8 Gb FC connectivity in their SAN will benefit from the upshift in throughput, as native 8 Gb disks appear and enterprise arrays are redesigned to accept them, just as devices like the DMX-4 from EMC benefited from 4 Gb FC back ends.

IP Storage: iSCSI and NAS

As far as iSCSI goes, those of us who saw the promise of this technology can finally declare victory. Every storage device that matters offers iSCSI as a connectivity option, and most buyers are considering adopting it. It is being weighed fairly against FC, and the promise of reduced heterogeneity and cost are proving attractive to many. In fact, it is wrong to continually compare it against FC, since many iSCSI buyers would never adopt an FC SAN due to concerns about cost or learning curve. Indeed, much of the uptake in iSCSI comes from areas where SAN was never adopted, and iSCSI’s growth can be partly attributed to these happy customers spreading the technology wider than originally intended.

A hidden benefit of iSCSI adoption is the technologies and techniques that have come along with it. Clustering of smaller storage systems has become a common option for scalability, and has proven itself against old modular “head/shelf” arrays. Although the rate of adoption for security technologies like CHAP and IPsec in iSCSI remains low, they are far more common than their FC relatives. And Microsoft’s simplified and universal iSCSI drivers, which include multi-path and snapshot technologies, have been much more successful than their proprietary equivalents.

Let us not forget humble old network attached storage (NAS), either. File server consolidation to NAS filers continues to be a healthy (but less flashy) market, and NAS virtualization is on the rise as these devices proliferate. And some in the server virtualization community are beginning to consider NFS for their servers, especially when it comes to VMware. NAS definitely still has life and legs and will benefit from the shift to 10 Gb Ethernet just like iSCSI and FCoE.

The Future

As for the future, it is clear that most storage vendors are lining up behind Fibre Channel over Ethernet (FCoE) . Although true I/O virtualization, as envisioned by datacenter Ethernet (DCE) and InfiniBand, may not gain traction outside the largest data centers, FCoE seems to be the inevitable next generation for massive enterprise storage. Just about every vendor is committed to it, and the customers I have spoken to accept it as the future. Although 8 Gb FC might delay FCoE in some cases, it will almost certainly be the predominant SAN connectivity mechanism for large block storage devices within five years.

© sfoskett for Stephen Foskett, Pack Rat, 2008. | A Consultant’s View Of The Enterprise Storage Market
This post was categorized as Computer History, 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.

PVSCSI gives virtual machines direct access to SCSI and FC HBAs, and plays nicely with NPIV (Xensummit diagram by Fujitsu)

Functionally similar to VMware’s Physical Compatibility Mode for Raw Device Mode (RDM) volumes, PVSCSI enables certain applications that require direct SCSI communication to function in a virtual environment. Examples include Oracle RMAN, backup applications, and potentially SAN management software.

PVSCSI plays nicely with N_Port ID Virtualization (NPIV), too, so you don’t need to assign a physical HBA port to each guest – they can all share a port or two, and each would have his own N_Port on the Fibre Channel fabric.

In their Xensummit presentation about PVSCSI, Fujitsu showed impressive performance numbers, demonstrating that the technology doesn’t cause much of a performance hit even though it is substantially more complicated than the alternative approaches. I do wonder how PVSCSI managed to outperform Dom0 with 128k writes, but let’s chalk that up to insignificant variations in timing…

Now if only Xen would update the (3.2-era) readme files on their download page!

© sfoskett for Stephen Foskett, Pack Rat, 2008. | Xen 3.3 Update Brings Paravirtualized SCSI
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.

Real Video: The Next Wave of Virtualization

Server virtualization is pushing storage into a new world.  Luckily, N_Port ID Virtualization and 8 Gb Fibre Channel is here to deliver all the I/O these servers demand.  Ellen O’Brien of TechTarget interviewed me about storage virtualization after Storage Decisions last month, and the video is now live on their BitPipe site.

Topics covered include how server virtualization pushes I/O demands, N_Port ID virtualization, storage virtualization technologies, and management challenges.  We also talk about where these things are currently and how they can be used today.

Here are some of my trademark Pearls ‘o Wisdom:

• “Systems that, in the past, wouldn’t need high-speed storage, suddenly face a drought of throughput”
• “Without NPIV, storage devices tend to think they’re only talking to one server, but they’re not anymore”
• “We’ve got virtual paths to virtual servers, so let’s have virtual storage as well!”
• “It’s much harder to trace down a cable when that cable doesn’t exist”
• “It’s as if we all suddenly had 200 mph cars – that’s great, but can we ever use them?”

Watch the whole video and let me know what you think!

© sfoskett for Stephen Foskett, Pack Rat, 2008. | The Next Wave of Virtualization
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.