I know that there has been a lot of content already written in relation to the latest 7.0U2 release of vSAN. My good pal Duncan has done a considerable amount on work to highlight the new features, and has an excellent set of YouTube videos that you can review at your convenience. However, I thought I would create a bite-sized overview of some of the big ticket items that are in the vSAN 7.0U2 release, as many of my readers have asked me about some of these features in the past. I’m not covering all of the features, of which…
One of the most common requests in relation to vSAN performance is how much CPU and memory does vSAN actually consume on an ESXi host, i.e. what is the overhead of running vSAN. Through the vSAN Performance Service, we have been able to show both host and vSAN CPU usage for some time. However, up to now, we have only been able to show host memory usage, and not overhead attributed to vSAN. It has also been extremely difficult to determine how much memory vSAN required. Way back in 2014, with the first vSAN version 5.5 release, I wrote this…
Hot on the heels of the vSAN 6.7 release, a new performance checklist for vSAN benchmarking has now been published on our StorageHub site. This is the result of a project that I started a few months back with my colleague, Paudie O’Riordan. It builds upon a huge amount of groundwork that was already done in this area by Andreas Scherr, one of our Senior Solutions Architects here in EMEA. The aim of this checklist is to get the best possible performance out of your vSAN deployment, typically during the Proof Of Concept (PoC) stage. We’ve had many situations where…
ESXi 6.0 Update 3 is now available. This update is significant for vSAN customers as there are a number of performance related issues addressed. The KB article detailing vSAN performance improvements can be found here, and the ESXi 6.0 U3 release notes can be found here. I wouldn’t necessarily write a blog post to highlight a KB or update release, but I think the improvements that have been made to vSAN performance in this update are very significant. Improvements include enhancements to the way that we do logging. In vSAN, every I/O operation is logged before being processed. We have…
If you were wondering why my blogging has dropped off in recent months, wonder no more. I’ve been fully immersed in the next release of VSAN. Today VMware has just announced the launch of VSAN 6.2, the next version of VMware’s Virtual SAN product. It is almost 2.5 years since we launched the VSAN beta at VMworld 2013, and almost 2 years to the day since we officially GA’ed our first release of VSAN way back in March 2014. A lot has happened since then, with 3 distinct releases in that 2 year period (6.0, 6.1 and now 6.2). For…
This is a new feature in vSphere 6.0 that I only recently became aware of. Prior to vSphere 6.0, all the I/Os from a given virtual machine to a particular device would share a single I/O queue. This would result in all the I/Os from the VM (boot VMDK, data VMDK, snapshot delta) queued into a single per-VM, per-device queue. This caused I/Os from different VMDKs interfere with each other and could actually hurt fairness. For example, if a VMDK was used by a database, and this database issued a lot of I/O, this could compete with I/Os from the…
This week I had the opportunity to roll-out the HCIbench tool on one of my all-flash VSAN clusters (much kudos to my friends over at Micron for the loan of a bunch of flash devices for our lab). The HCIbench is a tool developed internally at VMware to make the deployment of a benchmark tool for hyper-converged infrastructure (HCI) systems quite simple. In particular, we wanted something that customers could use on Virtual SAN (VSAN). It’s an excellent tool for those of you looking to do a performance test on hyper-converged infrastructures, thus the name HCIbench. Please note that this…