A very quick “public service announcement” post this morning folks, simply to bring your attention to a new knowledge base article that our support team have published. The issue relates to APD (All Paths Down) which is a condition that can occur when a storage device is removed from an ESXi host in an uncontrolled manner. The issue only affects ESXi 6.0. The bottom line is that even though the paths to the device recover and the device is online, the APD timeout continues to count down and expire, and as a result, the device is placed in APD timeout state. This obviously has an impact on virtual machines, workloads, etc, that are using this device.
Unfortunately there is no resolution at this time, but there are some workarounds detailed in the KB article. For those of you who dealt with APD events in earlier versions of vSphere, you’ll know the drill.
The KB article is 2126021. Note that this doesn’t affect all APD behaviors. Most APD events are handled just fine. However I’d urge you to take a quick read of the KB just to familiarize yourself with the behaviour and workarounds while we work on a permanent solution.
This question has come up on a number of occasions in the past. It usually comes up when there is a question about scalability and the number of disk drives that can be supported on a single host that is participating in Virtual SAN. The configurations maximums for a Virtual SAN node is 5 disk groups, with each disk group containing 1 flash device and up to 7 capacity devices (these capacity devices are magnetic disks in hybrid configurations or flash devices in all-flash configurations). Now the inevitable next question is how is this configuration implemented on a physical server. How can I get to 35/40 devices in a single server. There are a few ways to do it.
In Virtual SAN 6.0, a new snapshot format was introduced called vsanSparse. This improves snapshot functionality by leveraging the new VirstoFS on-disk format used with VSAN 6.0. I had a question recently about what would happen if I migrated a VM with a traditional vmfsSparse/redo log type snapshot. The question was whether or not it would be converted to the new vsanSparse format. Similarly, what if a VM with a vsanSparse snapshot was migrated from VSAN to a traditional VMFS/NFS datastore? Would it also be converted between formats? I decided that the only way was to try it out.
I already wrote an article on the NexentaConnect for VSAN product after seeing it in action at VMworld last year. More recently, I had the opportunity to play with it in earnest. Rather than giving you the whole low-down on NexentaConnect, instead I will use this post to show the steps involved in presenting a file share built by NexentaConnect to a VM. In this case, the VM and the file share both reside on Virtual SAN. I will also show you how to simply revert to a point-in-time snapshot of the file share using NexentaConnect. To answer the common question, “can VSAN do file shares as well as storing virtual machines?”, the answer is yes. This post will show you how.
I’ve had an opportunity recently to get some hands-on with HyTrust’s Data Control product to do some data encryption of virtual machine disks in my Virtual SAN 6.0 environment. I won’t deep dive into all of the “bells and whistle” details about HyTrust – my good buddy Rawlinson has already done a tremendous job detailing that in this blog post. Instead I am going to go through a step-by-step example of how to use HyTrust and show how it prevents your virtual machine disk from being snooped. In my case, I am encrypting virtual machine disks from VMs that are deployed on VSAN, as I have had this question in the past, i.e. can VMDKs on VSAN be encrypted? The answer is yes. This post will show you how.
Is it just me, or does VMworld seem to come around quicker these days? Anyway, it is great to have a couple of sessions in again this year, and yes – you guessed it, these are VSAN sessions once again. However, since I first posted this article, the content catalog for VMworld 2015 is now live.
STO4572 – Successful Virtual SAN Evaluation/Proof-Of-Concepts
This is an update on last year’s VSAN Proof-Of-Concept talk. A lot has changed in the last year, and the idea of this session is to fill you in on all the potential gotchas that you might encounter when trying to evaluate VSAN. I’ll be co-presenting this with Julienne Pham of VMware who has built up a wealth of field experience on VSAN. We’ll cover everything you need to know, including how to conduct various failure scenarios, and get the best performance. Thinking about deploying VSAN? This is one not to miss.
Regular readers will know that I normally blog about the technical aspects of storage, as opposed to doing opinion pieces. However there have been a number of articles published recently questioning the value of VMware’s Virtual Volumes, commonly referred to as VVols. In general, the pieces I have read ask whether or not VVols (or to be more accurate, per-VM granularity feature of VVols) adds value when NFS is already doing per-VM granularity in the form of files. The point that was missed in these pieces is that VVols is so much more than per-VM granularity. I’ve just come back from some great VMUG events in Frankfurt, Germany and Warsaw, Poland where I presented on the value of VVols to our users. I therefore thought it opportune to post about the other benefits of virtual volumes. Continue reading →