A number of you have reached out about how to change some of the settings around path policies, in particular how to set the default number of iops in the Round Robin path selection policy (PSP) to 1. While many of you have written scripts to do this, when you reboot the ESXi host, the defaults of the PSP are re-applied and then you have to run the scipts again to reapply the changes. Here I will show you how to modify the defaults so that when you unclaim/reclaim the devices, or indeed reboot the host, the desired settings come…
In this post, I want to look at some fail-over and load balancing specific to ALUA (Asymmetric Logical Unit Access) arrays. In PSA part 3, we took a look at the different Path Selection Plugins (PSP), but for the most part these were discussed in the context of Active/Active arrays (where the LUN is available on all paths to the array) and Active/Passive arrays (where the LUN is owned by one controller on the array, and is only visible on the paths to that controller). ALUA provides a standard way for discovering and managing multiple paths to LUNs. Prior to…
So far in this series, we have looked at the Pluggable Storage Architecture (PSA) and MPPs (Multipath Plugins). We have delved into the Native Multipath Plugin (NMP), and had a look at its sub-plugins, the Storage Array Type Plugin (SATP) and Path Selection Plugin (PSP). We have seen how the PSA selects an MPP, and if that MPP is the NMP, how the NMP selects an SATP and PSP. Note – if you are having trouble following all the acronyms, you are not the first. There is a glossary at the end of the first blog post. And if we…
Regular readers of my VMware Storage Blog will be no stranger to Nimble Storage. I’ve blogged about them on a number of occasions. I first came across them at a user group meeting in the UK & I also wrote an article about them when they certified on VMware’s Rapid Desktop Program for VDI. Nimble Storage have been in touch with me again to share details about their new 2.0 storage architecture. After a very interesting and informative chat with Wen Yu of Nimble, I’m delighted to be able to share these new enhancements with you, in this first post…