Well, I’m settled down in front of the telly to watch Andy Murray in the semi-finals of Wimbledon. If he gets through to the final I’ve promised my girlfriend bottle of champagne and strawberries when its on. I’ve been pretty quiet in recent weeks on the blogging front – that’s because I’ve been stuck with my head in my vSphere4 book and teaching courses. I’ve a couple of weeks off to R&R from my travels and get the book sown up. The last big push!

Anyway, the title of this blog post concerns using MRU in ESX 3.x.x. I first picked up on this on Chad Sakac’s virtualgeek blog – and it’s pretty devestating. Although Chad’s a EMC guy he quite frequently flags up VMware/Storage issues which can affect everyone. If MRU isn’t configured by a script – then every time you reboot an ESX host the LUN ownership can change. The net affect is all the I/O traverses one path. Anyway, Chad explains much better than I could check out these posts:

http://virtualgeek.typepad.com/virtual_geek/2009/04/are-you-stuck-with-a-single-really-busy-array-port-when-using-esx-script-for-balancing-multipathing-in-esx-3x.html

http://virtualgeek.typepad.com/virtual_geek/2009/04/understanding-mru-behavior-in-vmware-esx-3x.html

Incidentally, this issue has been fixed in ESX4….

This entry was posted on Friday, July 3rd, 2009 at 1:44 pm and is filed under ESX. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.