Very exciting day today at VMware – Virtual SAN or VSAN has been officially announced. If you weren’t able to attend, here are some of the interesting parts of the announcement: 32 node support (up from the 16 node support announced at Partner Exchange last month, and up from the 8 nodes which we supported during the beta) 2 million IOPS (using IOmeter 100% read, 4KB block size). Also 640K IOPS achieved with 70/30 read/write ratio, 4KB block size and 80% random. 3200 virtual machines (100 per node) 4.4 PB of storage (using 35 disk per host x 32 hosts…
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.
[Updated: 17th Feb 2016] 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 [5.5] 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…
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…
For those of you participating in the VMware Virtual SAN (VSAN) beta, this is a reminder that there is a VSAN Design & Sizing Guide available on the community forum. It is part of the Virtual SAN (VSAN) Proof of Concept (POC) Kit, and can be found by clicking this link here. The guide has recently been updated to include some Host Memory Requirements as we got this query from a number of customers participating in the beta. The actual host memory requirement directly related to the number of physical disks in the host and the number of disk groups…