Horizon View 7 on VSAN – Policies Revisited

It has been some time since I last looked at Horizon View on Virtual SAN. The last time was when we first released VSAN, back in the 5.5 days. This was with Horizon View 5.3.1, which was the first release that inter-operated with Virtual SAN. At the time, there was some funkiness with policies. View could only use the default policy at the time, and the default policy used to show up as “none” in the UI. The other issue is that you could not change the default policy via the UI, only through CLI commands. Thankfully, things have come a long way since then. In this post, I will look at how Horizon View 7 inter-operates with Virtual SAN 6.2, concentrating mostly on policies. However, Horizon View 7 also has new vmFork/Instant Clone technology and AppVolumes, and I hope to be able to do some posts on those features running on top of VSAN going forward.

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VSAN 6.2 Part 12 – VSAN 6.1 to 6.2 Upgrade Steps

I’ve already written a few articles around this, notably on stretched cluster upgrades and on-disk format issues. In this post, I just wanted to run through the 3 distinct upgrade steps in a little more detail, and show you some useful commands that you can use to monitor the progress. In a nutshell, the steps are:

  1. Upgrade vCenter Server to 6.0U2 (VSAN 6.2)
  2. Upgrade ESXi hosts to ESXi 6.0U2 (VSAN 6.2)
  3. Perform rolling upgrade of on-disk format from V2 to V3 across all hosts

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VSAN 6.2 Upgrade – Failed to realign objects

A number of customers have reported experiencing difficulty when attempting to upgrade the on-disk format on VSAN 6.2. The upgrade to vSphere 6.0u2 goes absolutely fine; it is only when they try to upgrade the on-disk format, to use new features such as Software Checksum, and Deduplication and Compression, that they encounter this error. Here is a sample screenshot of the sort of error that is thrown by VSAN:

locked or lack of vmdk descriptor fileOne thing I do wish to call out – administrators must use the VSAN UI to upgrade the on-disk format. Do not simply evacuate a disk group, remove it and recreate it. This will cause a mismatch between previous disk group versions (v2) and the new disk group versions that you just created (V3). Use the UI for the on-disk format upgrade.

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VSAN 6.2 Part 11 – Support for higher FTT with larger VMDKs

In the VSAN 6.0 Design & Sizing Guide, a caveat was placed around the size of a VMDK, and the Number of Failures to Tolerate (FTT) number. It reads like this:

“If the VMDK size is greater than 16TB, then the maximum value for NumberOfFailuresToTolerate is 1.”

I’m pleased to say that this restriction has been lifted in VSAN 6.2.

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Component Metadata Health – Locating Problematic Disk

I’ve noticed a couple of customers experiencing a Component Metadata Health failure on the VSAN health check recently. This is typically what it looks like:

component-metadata-healthThe first thing to note is that the KB associated with this health check states the following:

Note: This health check test can fail intermittently if the destaging process is slow, most likely because VSAN needs to do physical block allocations on the storage devices. To work around this issue, run the health check once more after the period of high activity (multiple virtual machine deployments, etc) is complete. If the health check continues to fail the warning is valid. If the health check passes, the warning can be ignored.

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Essential Virtual SAN (6.2) available for pre-order

book-edition2Our friends over at Pearson and VMware Press have informed us that the second edition of the Essential Virtual SAN book (that I wrote with Duncan Epping) is now available for pre-order on Amazon. It looks like it will be available on June 13th, but VMware Press have told us that they will do what they can to pull the date in a little closer. This new edition covers all of the new features added to Virtual SAN, up to the latest (yet to be released) VSAN 6.2. Here’s some blurb on the new edition, which gives a little insight into the new content:

Fully updated for the newest versions of VMware Virtual SAN, this guide show how to scale VMware’s fully distributed storage architecture to meet any enterprise storage requirement. World-class Virtual SAN experts Cormac Hogan and Duncan Epping thoroughly explain how Virtual SAN integrates into vSphere 6.x and enables the Software Defined Data Center (SDDC). You’ll learn how to take full advantage of Virtual SAN, and get up-to-the-minute insider guidance for architecture, implementation, and management.

If you want to order it at a local book store, here are the ISBN details:

  • ISBN-13: 978-0134511665
  • ISBN-10: 0134511662

Hope you find it useful. And thanks to my co-author Duncan, a consummate professional. It has been great working with you once again on this new edition of the book.

PrimaryIO announce VAIO (I/O filter) for cache acceleration

primaryio-logoI got a bit of a surprise a few weeks back when I noticed a register article by Chris Mellor stating that PrimaryIO (previously CacheBox) had announced a new cache acceleration I/O filter for vSphere. We first announced plans for VAIO (vSphere APIs for I/O Filters) back at VMworld 2014. VAIO allows VMware partners to plug their products/features directly into the VM I/O Path which in turn will give our customers access to 3rd party storage services/features like deduplication, compression, replication or encryption which may not be available on their storage array. Or in this case, a cache acceleration feature. I wasn’t aware of any announcement internally at VMware, so reading it on the register came as a bit of a surprise. I know that other partners such as SanDisk and Infinio are also working on cache acceleration products. However this was the first time I heard of PrimaryIO developing a cache acceleration filter.

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