I had the pleasure (?) recently of troubleshooting some backup issues on my vSphere Data Protection Advanced (VDPA) setup. To be honest, I had not spent a great deal of time on this product recently, other than a few simple backup and restores. However, in my new role I now have a number of other projects which requires me to understand this product’s functionality a bit more. When things were not going right for me though, I spent a lot of time searching for some log files which might give me some clue as to the nature of my problem. After some assistance from some of the GSS guys based in Cork, we narrowed it down.
For me, the install and configure part went fine. I could also create backups with relative ease. The issue related to running the backups in certain environments, which were failing. So how then could I determine why this was happening?
There are many occasions where the information displayed in the vSphere client is not sufficient to display all relevant information about a particular storage device, or indeed to troubleshoot problems related to a storage device. The purpose of this post is to explain some of the most often used ESXCLI commands that I use when trying to determine storage device information, and to troubleshoot a particular device.
Following on from my recent post on how to reclaim disks that were previously used by VSAN, I was asked how one can remove a disk group from a host that is participating in a VSAN cluster. This is quite straight forward, but there is one minor caveat and it relates to whether the VSAN cluster has been setup in Automatic Mode or Manual Mode. If you want to learn more about the behaviour of the different modes, you can read up on it here.
A number of customers have raised this question. How do you reclaim disks which were once used by VSAN but you now wish to use these disks for other purposes? Well, first off, if you are using some of the later builds of VSAN and you place the host into maintenance mode and remove the disk group from the host, this will automatically remove the partitions from the disks and you are good to go with reusing these disks for some other purpose. However, if you do something such as reinstall ESXi on the host but do not go through the appropriate VSAN clean up steps first, then there may still be VSAN partition information on the disks. So how do you go about cleaning up these disks?
This is an interesting announcement for those of you following emerging storage technologies. We’ve been talking about flash technologies for some time now, but for the most part flash has been either an SSD or PCIe device. Well, we now have another format – DIMM-based flash storage device. And VMware now supports it.
This is an issue which has caught a number of customers out during the Virtual SAN beta, so will probably catch some folks out when the product goes live too. One of the requirements for Virtual SAN (VSAN) is to allow multicast traffic on the VSAN network between the ESXi host participating in the VSAN Cluster. However, as per our engineering lead on VSAN, multicast is only used for relatively infrequent metadata operations. For example, object creation, change in object status after a failure and publication of statistics such as a significant change of free disk space (the publication of statistics is throttled so that only significant changes will cause an update, so these are also very infrequent events).