Comments on: Upgrading a RAID Array

By: Reeves Little

Reeves Little — Wed, 22 Aug 2007 15:41:03 +0000

Yep, you can put in a larger drive… but it will be the same size as the other drives in the RAID.

So, if your 250 gb drive fails and you put in a 500 gb drive you’ll have half the storage just sitting dormant.

By: Alex

Alex — Tue, 21 Aug 2007 22:23:20 +0000

Since my last comment I asked LSI and they claimed it would not work, but the way their tech described it I think he didn’t understand and suspect it can work.

The difficult part is that you can’t resize the disks. The MegaRaid will not support logical drives more than 2TB and its hard to resize an existing disk. But I should be able to add an extra logical disk and add it as a second volume. So I don’t get a full 4TB volume or anything (unless I do something like have Windows format it as JBOD) but I should be able to get a couple of smaller volumes.

By: Anthony Pittarelli

Anthony Pittarelli — Tue, 21 Aug 2007 22:17:46 +0000

im having the same troubles with upgrading, my raid card can accept it, but i dont know how to repartition the drives to take advantage of the space when im done

By: Alex

Alex — Mon, 13 Aug 2007 18:47:20 +0000

I’m not sure that is right- I’ve been reading the LSI card’s instructions and they are pretty clear that when a drive in the array fails it must be replaced by a drive the same size _or larger_. Now, presumably initially you don’t get to use the extra space, but once all the drives are new ones that are larger, in theory I should be able to set up a new “logical drive” on it. I just emailed their support to see if I can get an official word on whether this works.

While poking around in their admin software I noticed that two of the older 250gb drives (#4 & #5) have a couple of media errors recorded. Sounds like motivation to take care of this sooner rather than later.

By: Reeves Little

Reeves Little — Mon, 13 Aug 2007 10:27:49 +0000

Unfortunately, unless you’re using JBOD (just a bunch of disks, which you aren’t because your card doesn’t support it) you can’t add in disks of different sizes. The bad news is you’re in for either a laborious (lots of moving) or expensive (buying a new RAID card) switch.

RAIDs work great when used as intended, but try to get fancy (breaking the RAID to split off disks, changing to a new protocol) and it’ll bite you. My recommendation: you need new drives, that’s a forgone expense, bite the bullet and get a new card at the same time and your data will be fully redundant during the migration.