George Spelvin wrote: > I just discovered (the hard way, sigh, but not too much data loss) that a > 4-drive RAID 10 array had the mirroring set up incorrectly. > > Given 4 drvies A, B, C and D, I had intended to mirror A<->C and B<->D, > so that I could split the mirror and run on either (A,B) or (C,D). > > However, it turns out that the mirror pairs are A<->B and C<->D. So > pulling both A and B off-line results in a non-functional array. > > So basically what I need to do is to decommission B and C, and rebuild > the array with them swapped: A, C, B, D. > > Can someone tell me if the following incantation is correct? > > mdadm /dev/mdX -f /dev/B -r /dev/B > mdadm /dev/mdX -f /dev/C -r /dev/C > mdadm --zero-superblock /dev/B > mdadm --zero-superblock /dev/C > mdadm /dev/mdX -a /dev/C > mdadm /dev/mdX -a /dev/B That should work. But I think you'd better just physically swap the drives instead - this way, no rebuilding the array will be necessary, and your data will be safe all the time. /mjt - 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
