On Wed, 11 Aug 2010 02:55:44 -0700 (PDT) Jon Hardcastle <jd_hardcastle@xxxxxxxxx> wrote: > (my first attempt appears to have been bounced as the spam checker thought it had HTML in it?!) odd... came through ok for me the first time. > > Help! > > Long story short - I was watching a movie off my RAID6 array. Got a smart error warning > Aug 10 22:00:07 mangalore kernel: raid5: cannot start dirty degraded array for md4 This is the current problem. The array is dirty and degraded so there could theoretically be undetectable corruption. Chance is quite low but it is there so md won't start with out you acknowledging the risk by giving the --force flag to mdadm --assemble. Only do that if you are confident that your hardware is working correctly. > It appears sdc has an invalid superblock? > > This is the 'examine' from sdc1 (note the checksum) > > /dev/sdc1: ..... > Checksum : b335b4e3 - expected b735b4e3 Single bit error. That isn't good as it means some bit of memory or some bit on some bus somewhere cannot be trusted. It could be a transient thing and will never happen again. Or maybe not. Given the smart errors and the fact that you have had problems with the drive before it seem very likely that the problem is in that drive. I suggest unplugging it and leaving it unplugged. Some memory buffer in the drive is probably marginal. I don't think they use ECC memory. > > Anyways... I am ASSUMING mdadm has not assembled the array to be on the safe side? i have not done anything.. no force... no assume clean.. I wanted to be sure? You assume correctly. > > Should i remove sdc1 from the array? It should then assemble? I have 2 spare drives that I am getting around to using to replace this drive and the other 500GB.. so should I remove sdc1... and try and re-add or just put the new drive in? > > atm I have 'stop'ped the array and got badblocks running.... > Remove sdc and assemble the array with --force, and get a new device to replace /dev/sdc as soon as possible. NeilBrown -- 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
