I could really use some experienced guidance before proceeding. This 4 disk raid 5 (md0) holds media for MythTV and represents a great deal of work ripping my own DVDs. The system is on another drive, so most of the raid content is large-file and contiguous. System: /dev/sda Raid: /dev/sd[cdef]1 >From what I can tell, about a week ago, sde dropped out of the array. Ironically, Disk Utility says this drive is "healthy". With new disk in hand, I went to repair it a few days ago and found sdd dropped from the array as well. I ran bad-blocks -v on sdd which found more bad sectors. I have NOT tried to force assembly or recreation of the array. The mdadm -E results are at http://pastebin.com/7ng1bmyZ. The event counts: sdc : 42810 sdd : 42785 sde : 35760 sdf : 42810 I was thinking of doing a force assembly and then adding the new drive as a fourth. mdadm --assemble --force /dev/sd[cdf]1 Since these three are the closest event counts. Questions: 1. Would including sde (with the week-old data) in the forced assembly provide any additional information for the re-build? Is it better to start with a failed 3 drive array using the drive last in the array? 2. I read in the archives about ddrescue. Should I use it to copy some/all of the drives to new drives first? I am concerned the failed drive would not survive a consistency check and raid rebuild. Which drives? Even sdc has a non-zero read error rate, but is still considered "healthy". 3. How likely is the smartmontools firmware-bug the cause of these errors? These are all Samsung HD204UI drives. The raid has been running for about 2 years; although, I just recently updated to Ubuntu 12.04. Smartmontools was installed yesterday to produce the smart_all output: http://pastebin.com/bP1EruEK Much thanks for your expertise and time, Chris -- 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
