On Thu, 2006-06-08 at 14:15 -0400, Drew Weaver wrote:
Software RAID has failed us so many times in the past that I would never recommend it to anyone. Things like: the raid breaking for no reason and the server continually rebuilding over and over, and once a drive does finally die the other drive wasn't being mirrored properly (or wouldn't boot even though we manually sync'd the bootloaders as suggested.).
It has been nothing but a hassle, so if you need reliable data you need to find a card that works for you, I'm not sure why people are so ready to suggest software raid when the fact is its pretty unreliable.
I've had software raid work very well for years, but mostly on scsi controllers. I've even hotswapped replacement drives and rebuilt without shutting down. I like it because it's not unreliable on my hardware and since I use RAID1 I can recover data from any single disk by connecting it to any compatible controller. Or if a motherboard dies I can shove the drives in a spare chassis without worrying about whether it has exactly the same controller and raid configuration.
If you have a problem booting, you can boot the 1st install CD in rescue mode and fix the grub setup - and 'cat /proc/mdstat' will always show you if the mirrors are active.
I have heard of problems on SATA drives where errors aren't passed up to the md layer correctly but I don't have any experience with that myself. I'd probably go with a 3ware controller for SATA.