Virtual SAN already has a number of features and extensions for performance monitoring and real-time diagnostics and troubleshooting. In particular, there is VSAN Observer, which is included as part of the Ruby vSphere Console (RVC). Another new feature is the Health Check Plugin, which was recently launched for VSAN 6.0. However, a lot of our VSAN customers are already using vRealize Operations Manager, and they have asked if this could be extended to VSAN, allowing them us to use a “single pane of glass” for their infrastructure monitoring. That’s just what we have done, and the beta for the vROps…
With the release of VSAN 6.0, and the new all-flash configuration (AF-VSAN), I have received a number of queries around our 10% cache recommendation. The main query is, since AF-VSAN no longer requires a read cache, can we get away with a smaller write cache/buffer size? Before getting into the cache sizing, it is probably worth beginning this post with an explanation about the caching algorithm changes between version 5.5 and 6.0. In VSAN 5.5, which came as a hybrid configuration only with a mixture of flash and spinning disk, cache behaved as both a write buffer (30%) and read…
The more astute of you who have already moved to vSphere 6.0, and like looking at CLI outputs, may have observed some new columns/fields in the PSA claimrules when you run the following command: # esxcli storage core claimrule list –claimrule-class=VAAI The new fields are as follows (slide right to view full output): XCOPY Use Array XCOPY Use XCOPY Max Reported Values Multiple Segments Transfer Size ————— —————– ————– false false 0 false false 0 false false 0 false false 0 false false 0 false false 0 false false 0 false false 0 false false 0 false false 0 false …
There is a new snapshot format introduced in VSAN 6.0 called vsanSparse. These replace the traditional vmfsSparse format (redo logs). The vmfsSparse format was used when snapshots of VMs were taken in VSAN 5.5, and are also the format used when a snapshot is taken of a VM residing on traditional VMFS and NFS. The older vmfsSparse format left a lot to be desired when it came to performance and scalability. This KB article from our support team, indicating that no snapshot should be used for more than 72 hours, and snapshot chains should contain no more than 2-3 snapshots,…
Although most of my time is dedicated to Virtual SAN (VSAN) these days, I am still very interested in the core storage features that are part of vSphere. I reached out earlier to a number of core storage product managers and engineers to find out what new and exciting features are included in vSphere 6.0. The first feature is one that I know a lot of customers are waiting on – NFS v4.1. Yes, it’s finally here.
I was having some discussions recently on the community forums about Virtual SAN behaviour when a VM storage policy is changed on-the-fly. This is a really nice feature of Virtual SAN whereby requirements related to availability and performance can be changed dynamically without impacting the running virtual machine. I wrote about it in the blog post here. However there are some important considerations to take into account when changing a policy on the fly like this.
Hi all, A quick note to let you know about a new KB article that has recently been published which reports incorrect values for Outstanding IO in the VSAN Observer tool used for monitoring performance of VSAN deployments when using vSphere 5.5U2. KB 2091979 reports the issue as follows: Virtual SAN (VSAN) Observer graphs in the “VSAN Client”, “VSAN Disk”, “DOM Owner” or individual VSAN object on the “VM” tab show very high Outstanding I/O (OIO) value that is inconsistent with the actual I/O load. Here is a sample screenshot from my VSAN environment running vSphere 5.5U2. As you can see…