OK, I asked this question here before, and I got no answer whatsoever. I wasn't too concerned previously, but now that I lost the entire array the last time I tried to do a growth, I am truly concerned. Would someone please answer my question this time, and perhaps point me toward a resolution? The monthly array check just finished on my main machine. For many months, this happened at the first of the month and completed without issue and with zero mismatches. As of a couple of months ago, it started to report large numbers of mismatches. It just completed this afternoon with the following: RebuildFinished /dev/md0 mismatches found: 96614968 Now, 96,000,000 mismatches would seem to be a matter of great concern, if you ask me. How can there be any, really, when the entire array - all 11T - was re-written just a few weeks ago? How can I find out what the nature of these mismatches is, and how can I correct them without destroying the data on the array? How can I look to prevent them in the future? I take it the monthly checkarray routine (which basically implements ` echo check > /sys/block/md0/md/sync_action`) does not attempt to fix any errors it finds? I just recently found out md uses simple parity to try to maintain the validity of the data. I had always thought it was ECC. With simple parity it can be difficult or even impossible to tell which data member is in error, given two conflicting members. Where should I go from here? Can I use `echo repair > /sys/block/md0/md/sync_action` with impunity? What, exactly, will this do when it comes across a mismatch between one or more members? RAID6 array mdadm - v2.6.7.2 kernel 2.6.26-2-amd64 -- 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
