topic AutoRaid controllers in Disk Enclosures

AutoRaid controllers

CAULIER Remy — Thu, 31 May 2001 12:25:39 GMT

Hi all,
I have a HP Autoraid 12H with two controllers.
I created 6 LUNs, using the same controller and the other one as an alternate path.To increase performance, and since I read forum about it, How can I move three LUNs to the second controller, and using the old one as an alternate for those three? May I destroy all data ?
Thanks
Remy

Re: AutoRaid controllers

Maarten van Maanen — Thu, 31 May 2001 14:14:01 GMT

If you run a vgdisplay -v on your LV on the Autoraid you will see both the primary links as well as the alternate links.
You can use the vgreduce command to remove the primary paths on those PV's you want to use the second controllar as primary path. After this the alternate path will become primary automatically. Adding those PV's after that with vgextend will then add them again but this time as alternate link.
You won't have to delete any LUN's or LV's. A good backup is always nice. Better safe than sorry.
Another remark. You don't have to use many LUN's on the Autoraid, provided you use an even number for load-balancing on the controllers. I usually only create four since that gives me room for more if necessary.

Re: AutoRaid controllers

Bill McNAMARA_1 — Thu, 31 May 2001 14:34:24 GMT

no you won't destroy the data.
Remember you're not really moving the data, you are simply changing the default route which it's accessed by.

You do not do this at the array level. Don't change configuration of the 12H if you're happy with it. Just at the host/OS level configure lvm to access say luns 1 to 3 through X and luns 3 - 6 through Y.

You can do this with a vgextend and vgreduce if your Volume group is already active.

Strings your lvmtab, send an ioscan and vgdisplay the autoraid vg and we'll give your the command line.

Later,
Bill