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Pulling a drive to test RAID

If one drive is pulled, the software RAID at this point adds the hot-spare and starts rebuilding the RAID (this will take a few hours).

Important

You should not pull more than one drive. Since there is only one hot spare, pulling more than one drive can cause data loss.

Your environment is still be up, but some resources are reserved to assist in the rebuilding process.

Note

There are no current monitoring alerts for RAID health status (although, we are working to get this implemented in a future feature). Also, if a drive fails, adding a new drive to the RAID is not automatic and requires support interaction.

Example before pulling the drive​

[From storage]# cat /proc/mdstat

Personalities : [raid6] [raid5] [raid4] [raid0]
md50 : active raid0 md124[0] md126[1] md125[2] md127[3]
44989628416 blocks super 1.2 512k chunks

md124 : active raid5 dm-9[6] dm-0[2] dm-4[7] dm-7[3] dm-3[4] dm-1[5] dm-6[1]
11247538176 blocks super 1.2 level 5, 16k chunk, algorithm 2 [7/7] [UUUUUUU]
bitmap: 2/14 pages [8KB], 65536KB chunk

md125 : active raid5 dm-15[0] dm-17[1] dm-19[6] dm-24[2] dm-18[3] dm-23[7](S) dm-20[5] dm-16[4]
11247538176 blocks super 1.2 level 5, 16k chunk, algorithm 2 [7/7] [UUUUUUU]
bitmap: 1/14 pages [4KB], 65536KB chunk

md126 : active raid5 dm-10[0] dm-22[7](S) dm-13[1] dm-12[6] dm-8[4] dm-5[2] dm-14[5] dm-11[3]
11247538176 blocks super 1.2 level 5, 16k chunk, algorithm 2 [7/7] [UUUUUUU]
bitmap: 2/14 pages [8KB], 65536KB chunk

md127 : active raid5 dm-26[0] dm-30[7](S) dm-31[6] dm-27[5] dm-29[4] dm-28[3] dm-25[2] dm-21[1]
11247538176 blocks super 1.2 level 5, 16k chunk, algorithm 2 [7/7] [UUUUUUU]
bitmap: 1/14 pages [4KB], 65536KB chunk

unused devices: <none>

Console warning when the drive is removed​

[From storage]# WARNING: Your hard drive is failing

Device: /dev/bus/11 [megaraid_disk_01], failed to read SMART values

Status after pulling the drive (shows rebuild progress and estimated time to finish)​

[From Storage]# cat /proc/mdstat

Personalities : [raid6] [raid5] [raid4] [raid0]
md50 : active raid0 md124[0] md126[1] md125[2] md127[3]
44989628416 blocks super 1.2 512k chunks

md124 : active raid5 dm-9[6] dm-0[2] dm-4[7] dm-7[3] dm-3[4] dm-1[5] dm-6[1]
11247538176 blocks super 1.2 level 5, 16k chunk, algorithm 2 [7/7] [UUUUUUU]
bitmap: 1/14 pages [4KB], 65536KB chunk

md125 : active raid5 dm-15[0] dm-17[1](F) dm-19[6] dm-24[2] dm-18[3] dm-23[7] dm-20[5] dm-16[4]
11247538176 blocks super 1.2 level 5, 16k chunk, algorithm 2 [7/6] [U_UUUUU]
[>....................]  recovery =  0.9% (18209920/1874589696) finish=154.5min speed=200195K/sec
bitmap: 2/14 pages [8KB], 65536KB chunk

md126 : active raid5 dm-10[0] dm-22[7](S) dm-13[1] dm-12[6] dm-8[4] dm-5[2] dm-14[5] dm-11[3]
11247538176 blocks super 1.2 level 5, 16k chunk, algorithm 2 [7/7] [UUUUUUU]
bitmap: 2/14 pages [8KB], 65536KB chunk

md127 : active raid5 dm-26[0] dm-30[7](S) dm-31[6] dm-27[5] dm-29[4] dm-28[3] dm-25[2] dm-21[1]
11247538176 blocks super 1.2 level 5, 16k chunk, algorithm 2 [7/7] [UUUUUUU]
bitmap: 1/14 pages [4KB], 65536KB chunk

unused devices: <none>