EMC – VNX / CX4 LUN Allocation Owner and Default Owner

Mat’s been doing some useful scripting again. This time it’s a small PERL script that identifies the allocation owner and default owner of a pool LUN on a CX4 or VNX and lets you know whether the LUN is “non-optimal” or not. For those of you playing along at home, I found the following information on this (but can’t remember where I found it). “Allocation owner of a pool LUN is the SP that owns and maintains the metadata for that LUN. It is not advised to trespass the LUNs to an SP that is not the allocation owner. This introduces lag. The SP that provides the best performance for the pool LUN. The allocation owner SP is set by the system to match the default SP owner when you create the LUN. You cannot change the allocation owner after the LUN is created. If you change the default owner for the LUN, the software will display a warning that a performance penalty will occur if you continue.”

There’s a useful article by Jithin Nadukandathil on the ECN site, as well as a most excellent writeup by fellow EMC Elect member Jon Klaus here. In short, if you identify NonOptimal LUN ownership, your best option is to create a new LUN and migrate the data to that LUN via the LUN Migration tool. You can download a copy of the script here. Feel free to look at the other scripts that are on offer as well. Here’s what the output looks like.




Stormons Professional Edition Available

Disclaimer: I don’t work for Stormons, and I’ve not been compensated for this post. I just think it’s a cool product that is worth checking out.

Didier from Stormons recently got in touch to let me know there’s now a Professional version of the software available now as part of a subscription deal. I’ve previously covered Stormons here and here and think it’s pretty good stuff – and definitely worth checking out – particularly if you have a large environment to work with. Apparently EMC in Bangalore are heavy users of the product as well. The Professional Edition is offered on a subscription basis, and they’re running a discounted rate until May to celebrate the release. Find out more about it here. You can also still access the free edition from the downloads page.

EMC – Some new scripts

Mat has come up with a few new scripts – FlipFASTTiering and ReplicationCapacity. They’re PERL scripts that you can use to list / modify FAST Tiering scheduling and report on MirrorView replication data respectively. Hopefully you’ll find them of some use. Further information can be found on the Utilities page.