Sorry I see I missed a question. 2008/12/24 Bob Williams <linux@barrowhillfarm.org.uk>:
On Wednesday 24 December 2008 20:59:58 Rob OpenSuSE wrote:
2008/12/24 Bob Williams <linux@barrowhillfarm.org.uk>:
I know that RAID is not a substitute for backup, and run an rsync script every day to deal with that. Is a corrupt file system on one partition of a disk a likely problem, or would other partitions suffer in the same way. IOW are we talking about a disk hardware problem or a higher level software problem?
The partitions do isolate problems, the driver very much avoids writing outside the range of it's device. We're talking about fairly rare events, but which can be very unpleasant if they happen. Things like managing to write to the disk device directly, overwriting it (a reason not to over use root). There can be software errors. Sometimes memory goes bad. Occasionally corrupt transfers over PCI bus. You may do a bum kernel upgrade. With the RAID you shouldn't have a problem with bad blocks. Just remember RAID 5 in degraded mode, is far more likely to have a failure, than a single disk is. There's also a risk that a failing 'crazy' disk, might corrupt the parity data by reading and writing wrongly, so you do not have a single good copy after all. On con side, it's best to make a backup of your partition table, in case it gets overwritten by another OS, or the disk looses it for some reason, or has it corrupted. A few times I've had to recover data with gpart(8), and it requires patience, with 2TB of RAID5 that would not be my idea of fun Frankly, if the machine got the room for 4 disks, I'd have bought 2 WD 1.0 TB Green Power EADS, and used mirroring especially /boot & /, any crticial data. The disks aren't so expensive and that set up is much less fragile than RAID 5, and faster to recover with a disk failure. When you hit a snag, or need to get your data into another machine most likely with yet higher capacity disks, you can then just transfer 2 disk, not 3 as a complete array. http://www.baarf.com/ though written by DB ppl, has some good general technical explanations on the implications of using RAID 5. And it's characteristics. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org