This post came about after a brief discussion with my pal, Lee Dilworth. Although the outcome of this test has really nothing to do with vSAN, the behaviour was observed on certain Guest OS which were running on vSAN. I guess the first thing that needs to be made clear is that there is no support for in-guest UNMAP (or TRIM) for VMs running on vSAN at this time, although it is something we are examining very closely. So with this in mind, we had feedback to say that a test being run as part of a proof-of-concept was showing…
My Storage Policy Based Management (SPBM) presentation slide deck is now available online. This is the presentation that I delivered at a number of VMUG (VMware User Group) meetings this year in Europe, primarily Norway and Poland. SPBM is an integral part of VMware’s software defined storage vision, and is deeply integrated into vSAN, Virtual Volumes (VVols) and VAIO, the vSphere APIs for I/O Filters. Hope you find it useful. 2017 VMUG Storage Policy Based Management from Cormac Hogan
It seems that 2-node vSAN for ROBO (remote office/branch office) deployments are becoming more and more popular. The fact that one can now connect the 2 vSAN hosts at the remote office directly back-to-back without needing a 10Gb switch has reduced the cost extensively. And with the introduction of a vSAN Enterprise for ROBO license edition with vSAN 6.6.1, you get the full feature set of vSAN on 2-node deployments. This new edition builds on the vSAN Advanced edition, and enables the use of features like native encryption and stretched clusters on a per-VM pricing model for smaller sites. The…
I’m delighted to announce that I have been invited back to present at the next Poland/Polska VMUG, which will take place in Warsaw on Wednesday, October 25th, 2017. I have been asked to deliver the keynote at this VMware User Group meeting, and I will be using the opportunity to present on Storage Policy Based Management (SPBM), and how important it is to have a seamless, policy based approach to managing data. It would seem that I am one of the first speakers of the day, so I will have a lot of free time later in the morning and…
During one of our many discussions at VMworld 2017, I was asked about supporting Fault Tolerance on vSAN Stretched Clusters, more specifically SMP-FT. Now to be clear, we can support SMP-FT on vSAN since version 6.1. The difficulty with supporting SMP-FT on vSAN stretched cluster has always been the possible latency between the data sites, which could be up to as much as 5ms. This is far too high to support SMP-FT on a VM that has data replicating between data sites, and for that reason, we stated categorically that we could not support SMP-FT on VMs deployed on vSAN…
Many of you who are well versed in vSAN will realize that we released a Secondary Failures To Tolerate (SFTT) feature with vSAN 6.6. This meant that not only could we tolerate failures across sites, but that we could also add another layer of redundancy to each copy of the data maintained at each of the data sites. Of course the cross site replication (now referred to as PFTT or Primary Failures To Tolerate) is still based on RAID-1 mirroring and this continues to require a third site for the witness appliance, so that quorum can be obtained in the…
All three of my sessions from VMworld 2017 are now available on slide share. Lots of folks have been asking me for the content, so this is the easiest way of making them accessible. I just want to say thanks once more to my great co-speakers/co-presenters. I’m grateful to Cody Hosterman of Pure Storage for helping me out on the Core Storage session, and kudos must also go to my colleagues and good pals Duncan Epping and Andreas Scherr, who co-presented on the vSAN Top 10 and vSAN Networking sessions respectively. Enjoy!