Continuing on the series of vSphere 5.5 Storage Enhancements, we now come to a feature that is close to many people’s hearts. The vSphere Storage API for Array Integration (VAAI) UNMAP primitive reclaims dead or stranded space on a thinly provisioned VMFS volume, something that we could not do before this primitive came into existence. However, it has a long and somewhat checkered history. Let me share the timeline with you before I get into what improvements we made in vSphere 5.5.
I get a lot of questions around how the vSphere APIs for Array Integration (VAAI) primitives compare from a protocol perspective. For instance, a common question is to describe the differences between the primitives for NAS storage arrays (NFS protocol) and the primitives for block storage arrays (Fibre Channel, iSCSI, Fibre Channel over Ethernet protocols). It is a valid question because, yes, there are significant differences and the purpose of this blog post is to detail them for you.
During VMworld 2012 in San Francisco, I had a chance to catch up once again with the team from Tintri. My first introduction to Tintri was at last year’s VMworld, where they received runner-up in the ‘Hardware for Virtualization’ category by TechTarget for best of VMworld 2011. Well this year they went one better, and won the Best of VMworld 2012 Gold award in Hardware for Virtualization. And for good reason. Let’s see the enhancements to the Tintri platform over the last 12 months have brought.
Pure Storage are an all-flash enterprise storage company. I first met these guys at VMworld 2011 and was quite impressed by their product. Like many Flash Array vendors at the time, there wasn’t a great amount of vSphere integration features. However, with this latest release of Purity v2.5, Pure Storage are addressing this and more. I had a chance to meet and discuss these new features with Matt Kixmoeller & Ravi Venkat of Pure Storage recently. Not only are they now VMware-Ready certified, but they’ve got a whole bunch of integration features. Let’s have a look at the features that they have added to their new release.
VAAI NAS introduced the ability to create LazyZeroedThick & EagerZeroedThick disks on NFS datastores. Without VAAI NAS, one can only create thin VMDKs on NFS datastores. For those of you who are using VAAI NAS plugins, there is an important note in the 5.0U1 release notes that you should be aware of.
ESXi cannot distinguish between thick provision lazy zeroed and thick provision eager zeroed virtual disks on NFS datastores with Hardware Acceleration support
In this post, I want to highlight a number of storage improvements made in vSphere 5.1 that are going to be leveraged by the next release of vCloud Director.
EMC Isilon are providing even further vSphere integration features in their upcoming ‘Mavericks’ release of their OneFS operating system. This is great to see. The integration is in the area of vSphere APIs, both for Array Integration (VAAI) & Storage Awareness (VASA).
Let’s have a look at the VAAI enhancements first.
1. VAAI NAS integration
- Full File Clone/NFS File Copy – The Full File Clone primitive calls the storage array’s replication facility. In Isilon’s case, a writeable snapshot of the file is created, saving space since it does not need to clone the whole VM’s disk. This is very similar to the VAAI block primitive XCOPY. One difference I do need to call out however between block and NAS primitives is that the NAS Full File Clone primitive will only work with VMs that are not running. In other words, Storage vMotion operations do not use the Full File Clone primitive at this time, unlike Storage vMotion on block devices which support VAAI. I want to highlight that this is not a limitation in Isilon’s implementation; rather it is a limitation on the vSphere side. It is definitely something I want to see in a future implementation of VAAI.
- NFS Extended Stats – With NFS, vSphere only gets generic information about space consumption on Thin Provisioned datastores. The full details around the amount of space that is being consumed by an actual file on an NFS datastore at the back-end is not visible. This can lead to some space-management administration overhead as vSphere administrators may need to contact the storage admin for detailed information. In vSphere 5, all extended file and filesystem information are available via this primitive. For example, how much actual space is being consumed by a VMDK on the back-end can now be retrieved.
- NFS Reserve Space – In earlier versions of vSphere, there was no way for NFS datastores to create the equivalent of an “eager-zeroed thick” VMDK. In vSphere 5, with VAAI NAS support, you now have the ability to reserve the entire space for a VMDK on an NFS datastore with this Reserve Space primitive.
These primitives, of course, require the EMC Isilon VAAI NAS plugin, but this is easily installed via VUM, the VMware Update Manager. After watching some of the tests, the improvement is significant. An offline clone operation of a 120GB VM took about 7 minutes 15 seconds without VAAI. With VAAI, it took 1 minute and 29 seconds. This was almost 5 times faster. Nice!
vSphere Storage APIs for Storage Awareness, commonly referred to as VASA, is a set of APIs that permits storage arrays to integrate with vCenter for management functionality.
Isilon are now surfacing up a bunch of device capabilities with VASA. These are now visible in the vSphere client when examining datastores.
|ARCHIVE||Datastore resides on Isilon NL-series hardware|
|CAPACITY||Datastore resides on Isilon X-Series hardware|
|HYBRID||Datastore resides on a mixed Isilon hardware configuration|
|INVALID||Datastore resides on a mixed Isilon hardware configuration|
|PERFORMANCE||Datastore resides on Isilon S-Series hardware or SSD accelerated storage|
|ULTRA_PERFORMANCE||Datastore resides on Isilon S-Series hardware with SSD acceleration|
|UNKNOWN||The Storage Capability for this object is Unknown|
This is great to see. Isilon customers who deploy the VASA plugin along with upgrading to the Mavericks release can now reap the full benefits of VMware’s Profile Driven Storage feature. What this means is that deployments of VMs will always be error free, allowing you to select the correct datastore for your VM each & every time. The other benefit is that you can constantly check the compliance state of your VMs storage throughout its life-cycle (e.g. detect if someone inadvertently migrated to a lower tier of backing storage). You can learn more about Storage Profile but this blog post I did on the vSphere Storage Blog.
We don’t have enough vendors doing offloading with VAAI NAS, so it is a welcome sign to see Isilon introduce this. And I certainly like the VASA capability descriptions that they are surfacing up – I think this make it nice and clear to Isilon customers what sort of device(s) are backing their respective datastores.
EMC are a diamond sponsor at this years VMworld 2012 in San Francisco. I’m sure Jay, James and the rest of the Isilon team would be delighted to show you these new features. You’ll find those guys at booth 1203.
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