This post is to look at two different technologies available in vSphere to manage the queue depth on your ESXi host(s). A queue determines how many outstanding I/Os can be sent to a disk. In the case of vSphere environments, where many hosts can be doing I/O to the same shared disk device, it can be helpful to throttle the LUN queue depth from time to time when congestion arises. In this post, we will compare and contrast Adaptive Queues with Storage I/O Control (SIOC).
I recently got hold of a copy of the new V-locity 4 product from Condusiv which was released last month. Condusiv is the new name for Diskeeper, whom you may have heard of before. I first came across them as a provider of software which specialized in optimizing I/O, primarily by preventing file fragmentation on NTFS in a Windows Guest OS. I blogged about them in the past on the vSphere Storage Blog after some discussions around defragmentation in the Guest OS. The new feature takes a portion of memory and uses it as a block cache. I did some…
Following on from part 1 of the NFS Best Practices, part 2 is going to look at tuning from a vSphere perspective. As mentioned, our objective is to update the NFS Best Practice white paper which is now rather dated. There are quite a number of tunable parameters which are available to you when using NFS datastores. Before we drill into these advanced settings in a bit more detail, it is important to understand that the recommended values for some of these settings may (and probably will) vary from storage array vendor to storage array vendor. My objective is to…
There is a project currently underway here at VMware to update the current Best Practices for running VMware vSphere on Network Attached Storage. The current paper is a number of years old now, and we are looking to bring it up to date. There are a number of different sections that need to be covered, but we decided to start with networking, as getting your networking infrastructure correct will play a crucial part in your NAS performance and availability obviously.
Last week I published a blog article about new performance counters in vSphere 5.1 for monitoring Storage I/O Control (SIOC). Soon after publishing, I received a question about the siocActiveTimePercentage counter, which only ever showed 0% or 100% values.
There was an interesting question posted recently around how you could monitor Storage I/O Control activity. Basically, how would one know if SIOC had kicked in and was actively throttling I/O queues? Well, in vSphere 5.1, there are some new performance counters that can help you with that.