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
• Storage Changes in VMware ESX 3.5 Update 4
  
• Storage Changes in the VMware vSphere 4 Family

One first step is VMware’s whitepaper, “What’s New in VMware vSphere 5.0 – Storage“.

Licensing and Availability of Features

VMware has once again changed the licensing and pricing model, throwing the Internet into a tizzy:

• “Advanced” has been eliminated, moving up to “Enterprise”
• Pooled vRAM entitlements work across the entire vCenter environment
• New features like Policy-Driven Storage and Storage DRS (along with SIOC) are exclusive to “Enterprise Plus” licenses
• VAAI, PSP multipathing, and Storage vMotion are only found in “Enterprise”
• Thin Provisioning and VADP are available regardless of edition

VMware mucked with vSphere licensing again...

Major New vSphere 5 Storage Features

Storage DRS

Storage DRS is the world’s worst-kept secret, with everyone and his brother talking about it for over a year. Like the existing VM DRS capability, Storage DRS creates resource clusters and automatically moves VMs between them. Storage DRS uses utilization and performance metrics to make the call, and has three modes of operation. It sounds awesome, but it’s an Enterprise Plus-only feature.

Storage APIs – Storage Awareness (VASA)

There’s not much information presently, but a VAAI companion is introduced in vSphere 5: The vSphere Storage APIs for Storage Awareness (VASA) is a communication mechanism for vCenter to detect array capabilities like RAID Level, Thin Provisioning State, Replication State, etc. This will come in handy for all the other features in vSphere 5, especially policy-driven storage!

Policy-Driven Storage

Another new Enterprise Plus feature is Policy-Driven Storage. This allows storage tiers to be defined in vCenter based on SLA, performance, and other metrics which are used during provisioning, cloning, Storage vMotion, and Storage DRS. It leverages VASA for metrics and characterization and supports all arrays in the HCL, regardless of whether they’re NFS, iSCSI, or FC. It includes easy compliance status reporting in vCenter as well.

FCoE Software Initiator

Those of us “in the know” about storage expected VMware to add software FCoE support, so it’s no surprise that they did. This dramatically expands the potential FCoE footprint from just the few CNAs already supported in vSphere 4. It appears to be based on Intel’s OpenFCoE, since it shows up as “Intel Corporation FCoE Adapter” in the GUI!

vSphere Storage Appliance (VSA)

VMware enters the virtual storage appliance (VSA) market with their own offering, the vSphere Storage Appliance (also called VSA). Aimed primarily at the SMB market, it’s actually fairly clever, replicating storage between two or three nodes in a cluster for high availability and using NFS for access rather than iSCSI. And unlike the Celerra UBER that so many techies loved, the VMware VSA is ready for production use!

Existing Storage Features Enhanced in vSphere 5

VMFS 5

VMFS has been improved for scalability and efficiency, but the 2 TB limit on VMDKs remains (except for physical RDM). Only storage geeks like me need to worry about the specifics, but suffice to say that VMFS 5 requires less tuning and worrying and ought to scale and perform better thanks to increased maximums and leveraging the Atomic Test and Set (ATS) technology also used in VAAI. For newly-created volumes, there’s no more block size tuning, and alignment issues are addressed.

Storage APIs – Array Integration (VAAI 2)

See also VMware VAAI Storage Array Support in Plain English

VAAI has been revved, bringing back Thin Provisioning Stun (the AWOL “fourth primitive”) and adding NFS support.

There are now five block primitives for VAAI, depending on if you count thin space reclaim. This is really more of a bug fix than anything, since most folks assumed that the existing thin support already reclaimed deleted VMs and vMotioned VMDKs. I’m more interested in the addition of SCSI UNMAP in addition to WRITE_SAME! There’s also some additional T10 support, though I’m not clear on what it is or where it works.

We’ve also got VAAI for NFS environments now. NAS had sweet thin provisioning support even before block datastores, but the new Reserve Space command adds thick provisioning if that’s what you like. We’ve also got Full File Clone, which is like Full Copy for NFS but doesn’t work with Storage vMotion. And there’s some Extended Stats API to bring in more detail on file status. I also hear there’s an API for Native Snapshot Support, but it’s not widely discussed. Finally, note that NFS plugins come from vendors, not VMware as is the case for block VAAI.

Storage I/O Control

SIOC is enhanced for use in Storage DRS environments, becoming aware of the new datastore clusters. It also gets NFS support, and presumably uses VASA for metrics. But it’s still only available with Enterprise Plus licenses.

iSCSI Initiator GUI

The solid vSphere iSCSI initiator gets a friendly GUI for configuration. I like friendly iSCSI GUIs – just ask Microsoft!

Storage vMotion

The mechanism behind Storage vMotion has changed for a third time in as many releases, this time using “Mirror Mode” to mirror writes to in-progress vMotions. It also now supports migration of vSphere snapshots and Linked Clones. This can be offloaded for VAAI block, but not NFS.

vSphere Replication

New in vCenter Site Recovery Manager 5.0 is software-based replication. Although not technically a vSphere 5 feature, this is a major new storage feature in the VMware world. It allows any-to-any software-based storage replication for disaster recovery.

Stephen’s Stance

Once again, VMware added a ton of new storage enhancements to vSphere. With storage rapidly becoming the limiting factor in scalability and performance of virtual machine environments, this is no surprise. Also not surprising is the fact that major features like Policy-Driven Storage and Storage DRS (along with SIOC) are exclusive to “Enterprise Plus” licenses. I can’t blame VMware for making a buck, but it would be nice if more capabilities were available to the small shops!

I’ll be writing on all these features in detail shortly. Watch this space!

© sfoskett for Stephen Foskett, Pack Rat, 2011. | Storage Changes in VMware vSphere 5
This post was categorized as Enterprise storage, Features, Virtual Storage. Each of my categories has its own feed if you'd like to filter out or focus on posts like this.

Servers, storage, and networks may be interconnected, but most large IT organizations keep the administrative teams from mixing. But the next-generation virtual data center might change that!

Lots of my IT infrastructure management clients are talking about how the advent of Ethernet/IP and virtualization is changing the roles of storage, server, and network administrators. The evolution of the storage role in particular in enterprise IT organizations has been a topic of particular interest to me for a while: I definitely remember thinking about this as iSCSI and Cisco came on the scene a few years back, but the question of integration of storage, server, network, and application management areas is as old as IT.

Back in 2005, I wrote a column in Storage magazine, asking Who Watches the SAN? Although there were (and still are) reasons one might consider handing SAN management over to the network team, such as the use of iSCSI, Cisco FC, or (soon) FCoE, I concluded that many network teams just aren’t ready to take on SAN management. Storage is different – extremely sensitive to latency and outages and burdened with interconnect concepts that are similar, but not identical, to their network cousins. So most people are better off leaving SAN management in the hands of storage people, regardless of whether their SAN is made up of FC or iSCSI.

The Virtual Data Center

Things are changing, however. The modern data center is evolving to virtualize all three major IT infrastructure components: Servers, storage, and networks. Over the last year or so, we’ve seen the first fully-virtual infrastructure built, with all three areas combined in a single box, soup-to-nuts. Consider a VMware ESX server with virtual servers talking over virtual networks to a virtual storage array from FalconStor or LeftHand – it’s an entire data center in a box!

Server admins are normally tasked with everything “in the box”, including VMFS and virtual network connectivity, just as they always had to manage volume managers and path management software back in the “physical server” world. I doubt this will change. So we could see not just storage but network folks excluded entirely from the next-generation virtual datacenter!

This doesn’t have to be how things end up, though. I strongly believe that network and storage pros have critical insight into their areas, and cutting them out would be a tragic loss akin to what happened when open systems folks decided not to pay attention to the lessons of the mainframe generation. We would effectively repeat a decade of experience and learning that could, with minor modifications, be brought right into the modern world.

There are three things to do:

1. Re-combine the stovepipe IT infrastructure organizations (server, storage, network) into a single management organization with specialists in these areas and others like virtualization and cloud computing.
2. Spend the time and money to cross-train everyone to re-apply their experience and skills in this new world. Storage folks, for example, must know a good bit about server virtualization or their skills will have much less value!
3. Bring the mainframe, security, and records management folks to the party, too! They all have essential insights, and a failure to give them a seat at the table would be a critical loss.

Database and Applications

Then there are the DBAs and IT application folks. These teams have always been held at arms-length in the open systems world, and much closer on the mainframe side (especially the database people!) I think there has been a feeling that there were enough interests at the IT infrastructure planning meetings already without mixing them in as well! The current response is a service-based approach, where IT infrastructure adds an analyst role to develop SLAs and standard service offerings and act as a liaison between ITI and IT Apps.

This is probably enough for a conventional system, but there are changes here as well. Virtual appliances can step right into the apps arena, and the database/storage hybrid devices from Oracle/HP, Netezza, and the rest tromp right through the DBA world. Then there are the “webby dubby” (Web 2.0) storage services/devices like Amazon S3, Nirvanix, and EMC Atmos to consider.

Stephen’s Stance

I think we’re seeing another serious change to the status quo: Right after the data center is virtualized and IT infrastructure is recombined, applications themselves will fundamentally transform, demanding a merger of the current IT infrastructure and IT applications groups. This could all come within five years, or it could be delayed or diverted by organizational infighting and intransigence. It will be very interesting to see how it plays out!

© sfoskett for Stephen Foskett, Pack Rat, 2011. | Changes in Technology Drive Changes in IT Organizations and Roles
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.

How granular is your storage? This question is just as relevant today as when I first published this article in 2008!

Many storage challenges focus on correlating high-level uses of data (such as applications) with the nuts and bolts of storage infrastructure. These discussions often revolve around the conflict between data management, which demands an ever-smaller unit of management, and storage management, which benefits most from consolidation. Developing data management capability that is both granular enough for applications and scalable enough for storage is one key to the future of storage.

Storage Management: Scaling Up

As I discussed in a previous Sunday Series piece, Turning the Page on RAID, the data storage industry has traditionally focused on reducing granularity. Disk capacity has expanded, and RAID technology has multiplied this by combining multiple physical drive mechanisms into a single virtual one. Storage virtualization technologies, from the SAN to the server, have also often been touted primarily as a mechanism to reduce heterogeneity. From a technical perspective, therefore, granularity has been an obstacle to overcome.

The core organizational best practice for storage management is the reduction of complexity and the enforcement of standardization. Consolidation of storage arrays and file servers is a common goal, as IT seeks to benefit from economies of scale. The goal of both initiatives is the creation of a storage utility or managed storage service. This mirrors efforts on the server and network sides to consolidate and virtualize hardware.

Although both technological and organizational factors have traditionally driven granularity out of storage, this does not have to be the case. Virtual pools of storage are ideal for providing storage on demand, as disk-focused RAID groups give way to more flexible sub-disk storage arrangements. And an operational focus on standardized storage service offerings has the potential to enable scalable management of these smaller units.

Filing Service

File-based protocols would seem to have more potential for granular storage management, but they have been undermined by the hierarchical nature of modern file storage. Whether the connection to a file server uses NFS, CIFS, or AFP, the key unit of management is actually the shared directory, not the file. All files in the share \\firefly\backups would be located on the same server and would be managed as a unit.

NAS virtualization can change this somewhat, as can more specialized NAS servers. Although Microsoft DFS enables consolidation and virtualization of NAS shares, it does not allow subdivision of shares below the directory level – all files in a directory must be placed on the same server. Tricks like stubbing and links allow for some movement, but these do not solve the core issue. Specialized virtual NAS devices from F5 (the ARX, nee Acopia), NetApp, BlueArc, Symantec, and others have the ability to move files individually, providing as much a virtualized storage environment as any block-focused enterprise array. Avere is also beginning to talk about granular file management.

But even an ideal virtualized file server lacks the kind of granularity demanded by users. They care about data, not files, and most applications consolidate their data storage into a few files. Consider a database, for example, where users want each record treated uniquely but storage devices see just a few much larger files. We need a storage revolution, where someone creates an ideal storage platform in which each individual record or object includes custom metadata and is managed independently. This would truly be a massive change, however, and it is not clear that all applications will follow the object storage model of Google and Amazon.

Small is Beautiful

Barring a revolution in data management, our best hope is to allow greater granularity in storage management. As mentioned above, virtualization technology has the potential to enable management and protection of any unit of storage, right down to the individual block or record. But the reality of storage virtualization has not matched its promise.

What is needed is greater integration. Each layer of virtualization (file system, volume manager, hypervisor, network, array, and RAID) also hides necessary details from lower layers. Consider the case of a virtual server snapshot: The application and filesystem must be in a quiesced state to allow a snapshot to be taken at the storage level, but the storage array has no intrinsic information about how its capacity is used. A given LUN might contain dozens of servers on a shared VMFS volume, so all must be snapped together.

Integration can be enabled by sharing more information through APIs. VMware leverages Microsoft Volume Shadow Copy Service (VSS) integration for shared storage so a VMFS snapshot can call the operating system and even applications (Windows Server 2003 only, for now) to prepare the data. Similarly, VSS can communicate directly with supported iSCSI and Fibre Channel arrays, calling a snapshot at the right moment. And Microsoft is, no doubt, enhancing VSS as we speak.

As virtualization technology matures, expect this type of integration to improve. We hope to see more APIs exposed by VMware and Microsoft, allowing communication up and down the stack to break through the information barrier. Imagine a future where a standard API like VSS can pass a message through VMware, Xen, and Hyper-V to the underlying storage array to initiate a snap. I predict that this kind of integration-enabled granularity is not too far off.

© sfoskett for Stephen Foskett, Pack Rat, 2011. | Granularity: The Hidden Challenge of Storage Management
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.

Most important: Please register to be a marrow donor, especially if you might be a match for Nick Glasgow of EMC!

Misc

• The week of May 16 will forever be known as the week Twitter lost control of their eponymous service. There were some great posts, many of which went beyond whining and offered context on why Twitter is so important, but the one that sticks in my head most was a simple statement: “Goodbye People I Never Knew“
• But it wasn’t all bad news related to Twitter. Witness this awesome idea: A Modest Proposal For More Microstructure: Twitter /Locations
• My friend Donavon was featured in Baltimore Business Journal talking about his nifty home servers, and pictured with his humidor!
• A simple pearl of MBA wisdom: Ignore sunk costs
• And if you’re using LinkedIn, here are Five Dos and Don’ts
• The best new product of May? Easily it’s Lego’s new Frank Lloyd Wright models!
• Wilco’s new album was leaked, but rather than freak out they put up a free streaming version. It’s Grrrrrrreat!

Enterprise Computing

• vSphere finally hit, and lots of in-depth information appeared. I loved learning more about vSphere Memory/CPU Hotplug, a topic I knew nothing about! Also, see my Gestalt IT post answering Will the vSphere 4 Upgrade Require Another VMFS Update?
• The Doeswijk Data Model presents a wonderful way of thinking about storage capacity and growth.
• One of my favorite Windows 7/Server 2008 R2 features is the way that VHDs are handled: Learn more in Native VHD Support in Windows 7 and Less Virtual, More Machine – Windows 7 and the magic of Boot to VHD
• New to storage? Brent Ozar (aka The Man) wrote a series on SAN Multipathing. See Part 1: What are Paths? and Part 2: What Multipathing Does
• As everyone following my Twitter or Flickr feed knows, I was in Prague last week at the Sys-Con Cloud Expo. While there, I met up with a few others, including Guy Bunker, Sam Johnston, Roman Stanek, and others. See Time for a debrief!, Review of the Reviews, and the Photo Album

© sfoskett for Stephen Foskett, Pack Rat, 2009. | Back From The Pile: Interesting Links From Mid-May
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.

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
• Storage Changes in VMware ESX 3.5 Update 4
  

One first step is VMware’s whitepaper, “What’s New in VMware vSphere 4: Storage“.

Licensing and Availability of Features

The most important change at a glance is in the licensing model for VMware.

• A new low-end “standard” level includes all of the components a small business might need, including thin provisioning of storage, at a very attractive price.
• The “advanced” level includes advances in the area of data protection.
• At the “enterprise” level, live migration of storage is enabled.
• Top of the heap is “enterprise plus”, which enables the intriguing plug-in third-party multipathing support previously rumored.
• Enterprise customers with current support will get vStorage thin provisioning and data protection when they upgrade.

Each step up the licensing ladder enables important new storage features (source: VMware)

Thin Provisioning

One of the most widespread storage features is native thin provisioning. VMware ESX 4 will allocate storage in 1 MB chunks as capacity is used. This isn’t really completely new – similar support was enabled by default for virtual disks on NFS in VI 3, and thin provisioning could be enabled on the command line for block-based storage as well. It was also present in VMware’s desktop products, including my own copy of Fusion. And ESX allows thick-to-thin conversion during Storage VMotion.

The difference with vSphere 4 is that thin provisioning is fully supported and integrated into every version of ESX. Although many storage arrays now also offer thin storage, the addition of native, integrated thin provisioning right in ESX is huge. This alone will be a major capacity (and thus, cost) savings feature! VMware claims 50% storage savings in their lab tests.

Dynamic Expansion of VMFS Volumes

VMFS volumes can now grow (and, in some cases, shrink) online without resorting to spanning to a new LUN. Under vSphere 4, VMFS volumes can grow to take advantage of expanded LUNs (up to 2 TB per LUN). The old method still works as well, and multi-LUN spanned VMFS volumes can grow when any of their LUNs is expanded.

Enhanced Storage VMotion

Like thin provisioning, Storage VMotion has been elevated to first-class status, supported just about everywhere you’d want it. It’s in all the likely spots within vCenter.

Storage VMotion gives serious storage flexibility now, enabling (almost) any-to-any migration of VMFS volumes: Pick up a Fibre Channel, iSCSI, or NFS disk image and move it to another datastore running any of those protocols to convert live. And you can do thick-to-thin provisioning at the same time.

Under the hood, the whole infrastructure has been revised. Storage VMotion leverages VMware’s change block tracking instead of disk snapshots now, speeding up the migration process and reducing the (formerly excessive) memory and CPU requirements of Storage VMotion in 3.5. This is the same technology leveraged by vSphere’s High Availability features, by the way.

Pluggable Storage Architecture (PSA)

Only “Enterprise Plus” licensees will get to use it, but the vSphere family also sports a new pluggable storage architecture (PSA) which will initially be leveraged to deliver vendor-specific multipath support. Note that the native multipath support in vSphere continues to be a basic round-robin or fail-over system – it will not dynamically load balance I/O across multiple paths or make more intelligent decisions about which paths to use.

vSphere 4's Pluggable Storage Architecture allows third-party developers to replace ESX's storage I/O stack (source: VMware)

As you may gather from this VMware illustration (but would probably miss since it’s not all that comprehensible), there are two classes of third-party plug-ins:

1. Basic path-selection plugins (PSPs) will merely optimize the choice of which path to use, ideal for active/passive type arrays
2. Full storage array type plugins (SATPs) will allow load balancing across multiple paths in addition to path selection for active/active arrays

EMC also announced PowerPath/VE for vSphere, integrating their popular multi-platform path management software directly into ESX. It’s not clear at this point whether PowerPath will require an Enterprise Plus license (or if it will come with one) or if it will work with all editions, but I’m sure that will be clarified soon. My EMC contacts do tell me that PowerPath/VE is licensed on a per-socket basis (like VMware of yore) and that EMC sales reps have some room to get creative on licensing.

iSCSI Software Initiator Enhancements

It’s harder to claim it as a new feature, but the iSCSI software initiator has also been tweaked and tuned to use less CPU time and deliver better throughput. The iSCSI configuration process has also been smoothed out so one no longer needs to have a live Service Console connection in order to communicate with an iSCSI target. And changes made in the general tab are now global, so they’ll propagate down to each target. Bi-directional CHAP is also added, so the target can now be authenticated in addition to the initiator.

vSphere also includes a paravirtualized iSCSI driver (PVSCSI) which works like vmxnet to present a higher-performance iSCSI adapter within certain supported guest OSes.

More information on multipathing iSCSI can be found at Yellow Bricks and in Chad Sakac’s mega-post on the topic.

High-Performance I/O

vSphere really pours on the I/O power. They claim a 3x increase, to “over 300,000 I/O operations per second”, but mentioned in the launch that they’ve gotten to 400,000 in some workloads. This is really amazing, and if it’s true in real-world use means that VMware ESX can now host just about any application you can think of.

It’s funny, but just a few weeks before the announcement VMware’s Chief Data Center architect, Scott Davis, told me at Storage Networking World that vSphere would double I/O performance. I thought this was a bold statement at the time, but VMware went further in their official documents, claiming 3x improvement. Now we have an on-stage admission that it could be up to 4x! This is serious stuff, folks: Can VMware really do 400,000 IOPS?

One question is whether these IOPS improvements require the new VMDirectPath I/O for Storage, which binds a physical Fibre Channel HBA to a single guest OS, or if they’re generalized across all systems.

vCenter Improvements

vCenter now includes more storage information:

• Each VM and ESX in the inventory has a tab showing storage information and allowing users to set alarms on storage use – setting capacity alarms becomes extremely important when thin provisioning is used!
• vCenter inventory has a view showing datastore details
• There’s also a nice storage topology map

Data Protection APIs (Updated)

VMware also enhanced the APIs for consolidated backup (VCB) into “vStorage Data Protection”. Available only with Advanced or Enterprise licenses, these APIs allow enterprise backup vendors to develop specific integration with VMware without VCB in the middle.  All versions of ESX include this vStorage API and boast VCB support. Standard and Essentials licenses do not include vCenter Data Recovery, a standalone disk-to-disk backup capability for virtual machines.

Conclusion

vSphere is loaded with storage improvements, though many seem like incremental updates rather than new features. Admins will welcome thin provisioning support, and the full integration of Storage VMotion is certainly welcome, but I think the changes to vCenter will be most noticeable. I’ll be looking into EMC’s PowerPath/VE and the amazing I/O improvements as we move forward and learn more about the next ESX!

Duncan Epping posted much more vSphere Linkage on his Yellow Bricks blog if you’re interested in non-storage features. I also suggest reading Chris Evans’ outline of vSphere storage changes.

© sfoskett for Stephen Foskett, Pack Rat, 2009. | Storage Changes in the VMware vSphere 4 Family
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.

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.

For more information on Update 2, see my article, Storage Fixes in VMware ESX Server 3.5 Update 2.

Update 3 is not as important from a storage perspective, but there are some goodies in there:

• New VMDK recovery tool (nifty!)
• Storage tweaks like fixed multipathing on IBM SVC, interrupt coalescing on QLogic 4 Gb FC HBAs, and some bug fixes
• Expanded support for SATA (but not for VMFS), SAS, and some Broadcom NICs (but still no TOE)

Read on for more details!

VMDK Recovery Tool

ESX users with Update 3 get a nifty new script for deeper inspection of disk image files on VMFS. Although I haven’t had a chance to try it out yet, it appears to be related to VCB, in that it identifies which disk blocks make up a VMDK. But the VMDK Recovery script (which runs in Service Console on ESX – sorry, ESXi!) allows you to copy these blocks to a new file.

What good is this? Well, it could certainly be used to recover VMDK files from corrupted VMFS datastores, and could serve as an undelete feature as well. And as Rich Brambley points out on VM/ETC, it could be the basis for some nifty scripted backup and restore operations as well. I’m looking forward to seeing what happens with this, but it’s definitely a minor addition.

Storage Tweaks

Update 3 includes some minor tweaks and bug fixes in storage:

• ESX used to only support most-recently used (MRU) multipathing with IBM’s SAN Volume Controller storage virtualization platform, but Update 3 allows fixed policies to be used as well.
• The VMkernel iSCSI driver gets two new advanced configuration options (Disk.UseLunReset and Disk.UseDeviceReset) to control whether multipath failover will issue a LUN reset or target reset.
• SCSI sense codes are now included in /var/log/vmkernel by default.  This should assist in deep troubleshooting of storage problems.
• The lengthy iSCSI target discovery process that used to happen whenever a discovery address was added has been removed, speeding up iSCSI storage configuration.
• Users of QLogic 4 Gb Fibre Channel HBAs will now get updated firmware and a new performance feature called interrupt coalescing. As it sounds, IC will combine interrupts from multiple I/Os, improving overall performance by reducing the number of interrupts the CPU has to handle.

Note that VMware ESX 3.5 Update 3 still doesn’t really make maximal use of 10 Gb Ethernet. Besides the lack of TCP offload engine (TOE) support, the company still doesn’t make any speed claims when people step up to faster NICs. The Known Issues list specifically says it’s for connectivity, not performance. At least the QLogic iSCSI HBA support is pretty good.

[ad#banner]

© sfoskett for Stephen Foskett, Pack Rat, 2008. | Storage Changes in VMware ESX 3.5 Update 3
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.

Hopefully, VMware's three pillars (vCloud, vClient, and VDC-OS) are a little more solid (not to mention closer) than the Three Pillars of Creation in the Eagle Nebula

VMware packed a lot into their 2008 VMworld conference, including an outline of their “three pillars” strategy, focused on vClient, vCloud, and something they are calling the Virtual Datacenter Operating System. While it is debatable if this last item really is an operating system, it’s certainly a major strategic change in messaging.

VDC-OS is divided into four “vServices” (Management, Cloud, Application, and Infrastructure), and one core Infrastructure vService is vStorage. Since my focus is enterprise storage, I thought I would take a moment to examine the current and future status of vStorage.

EMC’s Chad Sakac has taken up the challenge of communicating vStorage to the world, in a post to his blog, a pair of YouTube videos (multipathing, I/O dedupe), and (apparently) a session or two at VMworld. But I’m not sure it’s really entirely clear just what vStorage is and what this means to existing and future VMware storage developments. So let’s dive in and take a look.

vStorage = Storage vService for VMware Infrastructure

Let’s get one thing out of the way immediately: VDC-OS is not a new product – it’s a framework to organize VMware’s existing and future datacenter-targeted products like ESX. The company is sweeping away the current hodgepodge of server product elements and placing them all into a more-organized structure called VDC-OS.

As such, the whole thing is not fully baked at present – there are lots of missing elements, and these point to future products from VMware and others. I applaud the organization, and feel that this is the first really viable next-generation datacenter vision that I have seen. It accurately reflects the current reality of the corporate data center and includes a migration path to take it to a compelling new level.

VMware has a realistic approach to bringing current datacenter elements into the future

As we can see in VMware’s diagram (above), the Virtual Datacenter OS is made up of VMware Infrastructure, with application vServices resting on infrastructure vServices or the cloud. This last bit is the fundamental breakthrough that makes VDC-OS more than just slideware – if it works, applications (virtual appliances) can transparently move from local infrastructure to cloud infrastructure owned and operated by others. It’s transformative, and if they pull it off, this could usher in a new datacenter world.

vStorage is one of the core infrastructure services, along with vCompute and vNetwork. Although it’s not entirely clear at this point, vStorage presumably includes all existing VMware storage technologies as well as the new APIs for multipathing and I/O deduplication highlighted at the show. I envision a future in which vStorage is a set of APIs for everything from I/O to device management, and VMware even includes virtual storage appliances in this umbrella.

vStorage: What’s In It?

At the very least, vStorage includes the following:

• VMFS for shared storage
• Thin Provisioning support in VMware Infrastructure is apparently coming in 2009, but is also apparently incompatible with fault tolerance.
• Linked Clones is another desktop technology coming to VI 2009.
• The Site Recovery Manager API has also become part of vStorage, though this isn’t getting much press.
• VMware Consolidated Backup (VCB) will also apparently be a vStorage API.
• The existing snapshot API will also presumably included.
• The new API for Multipathing covers the old generic native multipathing (NMP) from ESX as well as EMC’s most excellent PowerPath. The latter is presumably an extra-cost option that enables lots of niftiness, as demonstrated by Chad in this video.
• Another new API claims to deduplicate I/O, reducing traffic for certain supported disk operations, as demonstrated in Chad’s second video.

What is in and what is out is still kind of up in the air. But you can see that vStorage includes most of our old favorites (VMFS, SRM, VCB), some desktop elements (thin volumes, linked clones), and some new surprises (PowerPath, I/O dedupe). There is enough meat here to separate this from traditional slideware: VDC-OS has legs!

© sfoskett for Stephen Foskett, Pack Rat, 2008. | What is VMware VDC-OS vStorage?
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.