Software RAID problem - disks names change in case one fails
Hello, I'm testing a server before I put it in production, and I've got a problem with mdraid. The config: - Dell PowerEdge 800 - 4 x 250 Go SATA attached to the mobo - /boot 4 x 1 GB (1 GB available)in RAID1, 3 active + 1 spare - / 4 x 250 GB (500 GB available) in RAID5, 3 active + 1 spare No problems at install, and the server runs OK. Then I stop the server and remove /dev/sdb to simulate a hard disk failure that has caused a crash and a reboot. With the second disk removed the disks names are changed, the 3rd disk /dev/sdc becomes /dev/sdb and the 4th disk (that was the spare disk) /dev/sdd becomes /dev/sdc. During the boot process md detects that there is a problem, but then complains it can't find the /dev/sdd spare disk and the boot process stops with a kernel panic error. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: Software RAID problem - disks names change in case one fails
On Fri, 9 Sep 2005 [EMAIL PROTECTED] wrote: I'm testing a server before I put it in production, and I've got a problem with mdraid. The config: - Dell PowerEdge 800 - 4 x 250 Go SATA attached to the mobo - /boot 4 x 1 GB (1 GB available)in RAID1, 3 active + 1 spare - / 4 x 250 GB (500 GB available) in RAID5, 3 active + 1 spare No problems at install, and the server runs OK. Then I stop the server and remove /dev/sdb to simulate a hard disk failure that has caused a crash and a reboot. purrfect test and do the same for each disk it is pointless to have 1 spare disk in the raid array - have you evern wondered about other folks that try to build a sata-based raid subsystem ?? - how did their sata pass the failed disk test if it reassigns its drive numbers upon reboot With the second disk removed the disks names are changed, exactly that is the problem with scsi - pull the power cord from it to simulate the disk failure or pull the sata cable ... - in either case, if the disk drives rename itself, based on who's alive, raid won't work to boot after the failed disk ( but it will stay running until its booted ) the 3rd disk /dev/sdc becomes /dev/sdb and the 4th disk (that was the spare disk) /dev/sdd becomes /dev/sdc. thta's always been true of scsi During the boot process md detects that there is a problem, but then complains it can't find the /dev/sdd spare disk and the boot process stops with a kernel panic error. exactly c ya alvin -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: Software RAID problem - disks names change in case one fails
- have you evern wondered about other folks that try to build a sata-based raid subsystem ?? - how did their sata pass the failed disk test if it reassigns its drive numbers upon reboot With the second disk removed the disks names are changed, exactly that is the problem with scsi - pull the power cord from it to simulate the disk failure or pull the sata cable ... - in either case, if the disk drives rename itself, based on who's alive, raid won't work to boot after the failed disk ( but it will stay running until its booted ) the 3rd disk /dev/sdc becomes /dev/sdb and the 4th disk (that was the spare disk) /dev/sdd becomes /dev/sdc. thta's always been true of scsi That's why devfs used names that wouldn't change, e.g. /dev/scsi/bus0/host0/target0/lun0/part1 Of course that's been deprecated in the newer 2.6 kernels and I don't know udev so I don't know if it has a similarly helpful naming scheme...anyone? signature.asc Description: Digital signature
