topic Re: RAID 5 Expansion in Disk Enclosures

RAID 5 Expansion

D_82 — Fri, 14 May 2004 13:28:52 GMT

I have a Compaq Server that has an expansion bay. This bay has 3 9gig drives that are out of space. The OS is on one logical drive on the array and there is a data logical drive on the array. The 9Gb drives are out of space now (go figure). They have purchased 3 36Gb drives to replace the 9Gb drives. Can I swap the drives out one by one and let them rebuid and then go into the ACU and expand the data drive to use the new space? Or, am I going to have to back up the drives like they are, drop the backup back on the new drives and then use the ACU?

Thank you in advance for any help on this!

Re: RAID 5 Expansion

Uwe Zessin — Fri, 14 May 2004 14:30:12 GMT

I beleive this works on most SmartArray-based controllers, but I can't provide you with a list.

Please make a backup in advance, because this operation will take quite some time. If you pull one of the disks, you array will loose its RAID protection and when you stick in a new one (remember to switch of the spare if you've got one) it will do a recovery. So in the end your data is unprotected during each of the 3 rebuilds.

After the last rebuild you should see free space in the array. You can use this space to create additional logical disks or extend the current one.

Good Luck! And please let us know what controller you have and if it worked for you.

Re: RAID 5 Expansion

JohnWRuffo — Fri, 14 May 2004 14:30:40 GMT

Volume Expansion is really only available to a few O/S's... I am guessing you are on a Windows variety... and it's not one of them.
You could "quick and dirty" the expansion by doing just as you discribed. Then adding the newly available space to a big logical volume for say "data" then migrate your old data volume to the bigger logical.

If you can afford the downtime, you should consider the backup and restore process of expanding. That way you get what you really want... "logical volumes sized to your needs"

Take a read of: ftp://ftp.compaq.com/pub/products/servers/proliantstorage/drives-enclosures/hp%20hard%20drive%20replacement.pdf

Re: RAID 5 Expansion

D_82 — Fri, 14 May 2004 14:50:39 GMT

WOW John, that hyperlink was exactly what I have been looking for!

THank you for your responces!

Re: RAID 5 Expansion

JohnWRuffo — Fri, 14 May 2004 15:13:37 GMT

no prob! Glad to help