David Lethe wrote: >> -----Original Message----- >> From: linux-raid-owner@xxxxxxxxxxxxxxx [mailto:linux-raid- >> owner@xxxxxxxxxxxxxxx] On Behalf Of Tony Coffman >> Sent: Tuesday, August 26, 2008 10:33 AM >> To: linux-raid@xxxxxxxxxxxxxxx >> Subject: Device naming and raid1 >> >> I've have a Centos5 box running a software raid-1 set on a pair of >> > SATA > >> drives. >> >> The SATA controller or driver has a flaw. >> Every 150 days or so, one of the two drives will experience errors and >> fail. >> >> Subsequent tests always show the drive and cable to be ok. We bought >> > a > >> couple of replacement drives before we figured that out :-( >> >> On the last event this weekend, I went searching for a way to get the >> raid back online with no host downtime. I found the technique that >> deletes the drive and then brings it back online with a bus scan using >> the /sys filesystem delete and rescan entities. >> >> I didn't realize that you could also perform a rescan on a single LUN. >> I'll have to use that next time. >> >> My question - since I've done a delete/rescan bus operation, my device >> name and major,minor numbers have changed. >> >> Original >> [0:0:0:0] disk ATA ST3250410AS 3.AA /dev/sdc >> >> Current >> [0:0:0:0] disk ATA ST3250410AS 3.AA /dev/sdc >> >> If I re-add the device to the raid set using the new device name, will >> it cause any problems on the next boot? >> >> The drive appears to be fine. I can read all blocks with no errors. >> Partition table looks ok, etc.. >> >> In the future if I rescan just the single LUN, I'm pretty sure I won't >> run into again this but I'd like to avoid an outage on this event if >> possible. >> >> Thanks and regards, >> --Tony >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-raid" >> in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.htm >> > Don't be too quick to say the drive(s) are good, or for that matter, > making any assumptions about what is bad or good. (Well, OK, let's > assume the monitor is good). If the drives are reporting errors and > the drives fail, why not trap the error messages and do some diagnostics > while drives are still in that failed state? Error messages tell you > what the errors are. Make yourself a bootable CDROM or USB and next > time the drives lockup and/or start spitting out errors, then capture > everything. Then boot to the external device (do NOT cycle power), and > run one of many possible diagnostics to confirm or eliminate the disks. > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Thanks much for the reply. For the purposes of this discussion you can assume that I've already re-established confidence in the drive, the cable, and the controller and that the data on the drives is worthless and I just want to get maximum uptime without causing a raid assemble problem on the next reboot. Any idea on my original question? If I re-add the drive using the /dev/sdc name will I have problems on the next boot when the drive is named /dev/sda? Based on my experience with Linux and other software raid implementations, I'm strongly inclined to think that the device naming doesn't matter - the system will scan the drives at boot looking for raid sets and re-assemble them no matter what major and minor numbers or device names are. I'm not opposed to finding out the hard way but I'd really like to get a definitive answer now because by the time this system is next rebooted I'll probably have long forgotten about this. Regards, --Tony -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
