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: Upgrade vCenter Server to 6.0U2 (VSAN 6.2) Upgrade ESXi hosts to ESXi 6.0U2 (VSAN 6.2) Perform rolling upgrade of on-disk format from V2 to V3 across all hosts
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: One 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…
In this post, I want to talk about a feature called Problematic Disk Handling. Some history behind why we have such a feature can be found in this post. In VSAN 6.2/vSphere 6.0 U2, Problematic Disk Handling has been improved so that it will unmount a problematic disk/diskgroup for two reasons:
There might be a reason in VSAN stretched cluster environments or in 2-node VSAN ROBO deployments to change the witness appliance. The one thing to keep in mind is that you must use a witness appliance that has the same on-disk format as the rest of the disk groups in the cluster. Right now, there is a 6.1 version of the appliance and a 6.2 version of the appliance, so make sure that you select the correct one. Replacing the current witness with a new witness is very straight forward, and the tasks can be summarized as follows: Deploy the…
This is an exercise that we ran through in our lab environment, and we thought that the steps would be useful to share here. By way of introduction, our 4 node cluster is split into a 2+2+1 configuration, where there are 2 ESXi hosts on site A (VLAN 4), 2 ESXi hosts on site B (VLAN 3), and a third site, site C (VLAN 80), hosting the witness appliance (nested ESXi host). All sites are connected over L3. In other words, static routes are added to each of the ESXi hosts so that ESXi hosts on site A can reach…
If you’ve been following my series on VSAN 6.2 blog posts, you’ll be aware of a considerable number of new features, especially around space efficiency, such as deduplication and compression. On top of this, there is a new on-disk format (v3) and a new software checksum mechanism. All of these features introduce some capacity overhead in their own right, so as to allow administrators track where the storage consumption is occurring a brand new capacity view has been introduced with VSAN 6.2.
Many seasoned VSAN administrators will know how heavily we rely on VSAN Observer to get an understanding of the underlying performance of VSAN. While VSAN Observer is a very powerful tool, it does have some drawbacks. For one, it does not provide historic performance data, it simply gives a real-time view of the state of the system as it is currently, not what it was like previously. VSAN Observer is also a separate tool and is not integrated with vSphere web client, thus you didn’t have a “single pane of glass” view of the system. The tool is also complex,…