VSAN Part 32 – Datastore capacity not adding up

I was involved in an interesting case recently. It was interesting because the customer was running an 8 node cluster, 4 disk groups per host and 5 x ~900GB hard disks per disk group which should have provided somewhere in the region of 150TB of storage capacity (with a little overhead for metadata). But after some maintenance tasks, the customer was seeing only 100TB approximately on the VSAN datastore. This was a little strange since the VSAN status in the vSphere web client was showing all 160 disks claimed by VSAN, yet the capacity of the VSAN datastore did not…

Catch me at PEX 2015 – “Successful Virtual SAN POC” session

I’m sure many of you will be attending Partner Exchange next month in the Moscone Center in downtown San Francisco. I did not expect to be attending this year, but I got a request to co-present a Virtual SAN Proof Of Concept/Evaluation session. I’ve delivered a similar session at a number of EMEA VMUGs recently. This presentation seems to have been well received to date, and I’m hoping it will got down well at Partner Exchange also. The session details are as follows: STO4289 – Conducting a Successful Proof of Concept for Virtual SAN [update] I checked the schedule builder…

VSAN Part 31: Object compliance and operational status

In a previous post, I discussed the difference between a component that is marked as ABSENT, and a component that is marked as DEGRADED. In this post, I’m going to take this up a level and talk about objects, and how failures in the cluster can change the status of objects. In VSAN, and object is made up of one or more components, so for instance if you have a VM that you wish to have tolerate a number of failures, or indeed you wish to stripe a VMDK across multiple disks, then you will certainly have multiple components making…

VSAN Part 30 – Difference between Absent & Degraded components

As part of a quick reference proof-of-concept/evaluation guide that I have been working on, it has become very clear that one of the areas that causes the most confusion is what happens when a storage device is either manually removed from a host participating in the Virtual SAN cluster or the device suffers a failure. These are not the same thing from a Virtual SAN perspective. To explain the different behaviour, it is important to understand that Virtual SAN has 2 types of failure states for components: ABSENT and DEGRADED.

My VSAN Session from the Nordic VMUG

The folks from the Nordic VMUG team in Denmark were kind enough to record my Virtual SAN (VSAN) session in Copenhagen last week. If you are interested in VSAN, or considering a VSAN evaluation or Proof of Concept, then this might be worth watching. In it, I cover design considerations, troubleshooting tools, monitoring and performance, as well as some common gotchas. I close with some VSAN futures. Enjoy!

Tips for a successful Virtual SAN (VSAN) Proof Of Concept (POC)

Pretty soon I’ll be heading out on the road to talk at various VMUGs about our first 6 months with VSAN, VMware’s Virtual SAN product. Regular readers will need no introduction to VSAN, and as was mentioned at VMworld this year, we’re gearing up for our next major release. With that in mind, I thought it might be useful to go back over the last 6 months, with a look at some successes, some design decisions you might have to make, what are the available troubleshooting tools, some common gotchas (all those things that will help you have a successful…

vsan.resync_dashboard only reports VM resyncing, not templates

While doing some testing yesterday in our lab, we noticed that after we had placed a host participating in a VSAN cluster into maintenance mode and chose the option to evacuate the data from the host to the remaining nodes in the cluster, the “Enter Maintenance Mode” task was still sitting at 63% complete even though it seemed that the resynchronization of components was complete. For example, when we used the vsan.resync_dashboard RVC command, there were 0 bytes left to sync: > vsan.resync_dashboard /localhost/ie-datacenter-01/computers/ie-vsan-01/ 2014-11-06 12:07:45 +0000: Querying all VMs on VSAN … 2014-11-06 12:07:45 +0000: Querying all objects ..…