"Ashley M. Kirchner" <ashley@xxxxxxxxxx> writes: > 1. Should I use the BIOS to create/manage my RAIDs or should I let > linux do that for me? I prefer letting linux manage it. That way, you can replace the motherboard or controller without losing your raid array. > 2. Can I add drives to the RAID in the future and simply GROW it, > without losing information? Or am I going to be adding more RAID > volumes as I add pairs of drives? What I do is partition each drive into, say, ten partitions. Then I combine all sd*1 into md1, all sd*2 into md2, etc; and use LVM to combine the md* into a big volume group. Then, as long as I'm under 90% full, I can move data off the individual PVs, shut down the md* for that "slice", rebuild it to include a new drive, and re-add it to the VG. In fact, I just did that this weekend. I had five 200G drives, raid5 across them, in a seven slot chassis. I added two 750G drives, but had to remove one of the 200's to fit the third 750 in. So, I used one of the partitions on the 750 as temp space and rebuild the ten existing raids from raid5x5 to raid5x4, removing the fifth drive from each. Once they were all done, I physically swapped drives and built the raid3x3 slices on the 750's, moving the data off the temp partition once I had room for it elsewhere. pvmove md4 vgreduce foo md4 mdadm --stop md4 mdadm --create md4 ... pvcreate md4 vgextend foo md4 (it helps to "pvchange -x n" all of the slices you're migrating, ahead of time, so that you cut down on duplicate moves)
