On 07/26/2016 04:52 AM, Adam Goryachev wrote: > No, I'm saying that is an excellent idea, and it is exactly what I always do. > The problem is that you created the single large primary partition, and then > used the raw drive for the raid array instead of using the partition. Damn, that is exactly what I did, even though I intended to use sdc1 and sdd1. Checking bash_history for root, I find: mdadm --create --verbose --level=1 --metadata=1.2 --raid-devices=2 /dev/md4 /dev/sdc /dev/sdd then mkfs.ext4 -v -L data -m 0.005 -b 4096 -E stride=16,stripe-width=32 /dev/md4 So basically I just need to fix the partition table on sdc, that will leave both sdc and sdd with health partition tables and a primary partition of sdc1 and sdd1. I'll blow away the current degraded md4 and recreate md4 with mdadm --create --verbose --level=1 --metadata=1.2 --raid-devices=2 /dev/md4 /dev/sdc1 /dev/sdd1 mkfs.ext4 -v -L data -m 0.005 -b 4096 -E stride=16,stripe-width=32 /dev/md4 Then its just a matter of re-copying the data, uncommenting fstab and updating mdadm.conf? This even solved the mystery of where the original corruption came from. That's a hole in one. As for either shrinking the filesystem on sdc to fit on sdc1 and sdd1, is that worth attempting, or is it probably better to just blow away the existing array and then recreate it all as indicated above? If I can save the filesystem, I save a few hours of formatting, but I worry about the reliability of shrinking the filesystem. (there is plenty of room, I have 258G used out of 2.7T) What is the consensus? Is shrinking reliable, or is it something to consider as a worse case scenario (as in the hypothetical replacing of a disk that is slightly smaller than the failed one)? Thank you again for your help. Glad to see Murphy's law is still well in force and effect. (an entire PT mystery caused by some dummy that forgot to append the '1' during the mdadm --create -- who would have imagined :) -- David C. Rankin, J.D.,P.E. -- 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
