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…
Last week, I presented at the UK National VMUG. I took the opportunity to catch up with Darren Williams (Technical Director, EMEA & APAC) of WHIPTAIL who was also presenting at the event. My first introduction to WHIPTAIL came last year when I first met Darren at another user group meeting, and I posted about their XLR8R array on the vSphere storage blog. Darren & I discussed the changes which WHIPTAIL has undergone in the past 12 months since we last spoke, including the launch of a new range of scale out storage arrays, as well as the new features…