Log dari dmesg
[ 8.692351] md: raid6 personality registered for level 6
[ 8.692354] md: raid5 personality registered for level 5
[ 8.692355] md: raid4 personality registered for level 4
[ 8.692606] md/raid:md125: device sdb3 operational as raid disk 1
[ 8.692608] md/raid:md125: device sda3 operational as raid disk 0
[ 8.692858] md/raid:md125: allocated 3308kB
[ 8.692986] md/raid:md125: raid level 5 active with 2 out of 3 devices, algorithm 2
[ 8.692989] RAID conf printout:
[ 8.692990] --- level:5 rd:3 wd:2
[ 8.692991] disk 0, o:1, dev:sda3
[ 8.692992] disk 1, o:1, dev:sdb3
[ 8.693021] md125: detected capacity change from 0 to 523239424
[ 8.694665] md/raid:md127: device sdb2 operational as raid disk 1
[ 8.694667] md/raid:md127: device sda2 operational as raid disk 0
[ 8.694872] md/raid:md127: allocated 3308kB
[ 8.694891] md/raid:md127: raid level 5 active with 2 out of 3 devices, algorithm 2
[ 8.694892] RAID conf printout:
[ 8.694893] --- level:5 rd:3 wd:2
[ 8.694894] disk 0, o:1, dev:sda2
[ 8.694895] disk 1, o:1, dev:sdb2
[ 8.694916] md127: detected capacity change from 0 to 8072986624
Komputer tersebut gagal booting, yang selalu muncul errornya seperti baris 7 diatas. Akhirnya saya booting menggunakan Live USB Fedora 23, cara bisa dilihat di membuat live usb Fedora.
Setelah booting dari Live USB, cek partisi raid dengan perintah cat /proc/mdstat
cat /proc/mdstat
## output
Personalities : [raid6] [raid5] [raid4]
md124 : inactive sdc5[3](S) sdb5[1](S) sda5[0](S)
232439808 blocks super 1.2
md125 : active raid5 sdb3[1] sda3[0]
510976 blocks super 1.0 level 5, 512k chunk, algorithm 2 [3/2] [UU_]
md126 : inactive sdb1[1](S) sda1[0](S) sdc1[3](S)
5614906368 blocks super 1.2
md127 : active raid5 sdb2[1] sda2[0]
7883776 blocks super 1.2 level 5, 512k chunk, algorithm 2 [3/2] [UU_]
unused devices:
yang bermasalah ada di md125 dan md127. UU_ disitu berarti hardisk yang error adalah 1 partisi. U menanadakan partisi dari RAID.
Cek detailnya dengan mdadm
partisi md125
mdadm --detail /dev/md125
## output
/dev/md125:
Version : 1.0
Creation Time : Mon Jan 19 02:18:14 2015
Raid Level : raid5
Array Size : 510976 (499.08 MiB 523.24 MB)
Used Dev Size : 255488 (249.54 MiB 261.62 MB)
Raid Devices : 3
Total Devices : 2
Persistence : Superblock is persistent
Update Time : Sun Oct 4 21:57:10 2015
State : clean, degraded
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 512K
Name : localhost:boot (local to host localhost)
UUID : 351cbbd0:21c40094:a881de59:6aca605a
Events : 351
Number Major Minor RaidDevice State
0 8 3 0 active sync /dev/sda3
1 8 19 1 active sync /dev/sdb3
4 0 0 4 removed
partisi md127
mdadm --detail /dev/md127
## output
/dev/md127:
Version : 1.2
Creation Time : Mon Jan 19 02:18:15 2015
Raid Level : raid5
Array Size : 7883776 (7.52 GiB 8.07 GB)
Used Dev Size : 3941888 (3.76 GiB 4.04 GB)
Raid Devices : 3
Total Devices : 2
Persistence : Superblock is persistent
Update Time : Mon Oct 5 13:42:08 2015
State : clean, degraded
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 512K
Name : localhost:swap (local to host localhost)
UUID : 4e27d8d8:1356298c:59c72910:378bfb44
Events : 15566
Number Major Minor RaidDevice State
0 8 2 0 active sync /dev/sda2
1 8 18 1 active sync /dev/sdb2
4 0 0 4 removed
disini kelihatan partisi yang hilang adalah /dev/sdc3 untuk /dev/md125 dan /dev/sdc2 untuk /dev/md127. Tambahkan kembali partisi tersebut kedalam partisi RAID
mdadm /dev/md125 -a /dev/sdc3 mdadm /dev/md127 -a /dev/sdc2
check lagi status partisi RAID
cat /proc/mdstat
## output
Personalities : [raid6] [raid5] [raid4]
md125 : active raid5 sdc5[3] sda5[0] sdb5[1]
154958848 blocks super 1.2 level 5, 512k chunk, algorithm 2 [3/2] [UU_]
[==========>..........] recovery = 51.3% (39749448/77479424) finish=8.7min speed=71806K/sec
bitmap: 0/1 pages [0KB], 65536KB chunk
md126 : active raid5 sdc1[3] sdb1[1] sda1[0]
3743269888 blocks super 1.2 level 5, 512k chunk, algorithm 2 [3/2] [UU_]
resync=DELAYED
bitmap: 14/14 pages [56KB], 65536KB chunk
md124 : active raid5 sdc3[3] sda3[0] sdb3[1]
510976 blocks super 1.0 level 5, 512k chunk, algorithm 2 [3/3] [UUU]
md127 : active raid5 sda2[0] sdc2[3] sdb2[1]
7883776 blocks super 1.2 level 5, 512k chunk, algorithm 2 [3/3] [UUU]
Partisi yang telah selesai diperbaiki/recovery
cat /proc/mdstat
## output
Personalities : [raid6] [raid5] [raid4]
md124 : inactive sdc5[3](S) sdb5[1](S) sda5[0](S)
232439808 blocks super 1.2
md125 : active raid5 sdc3[3] sdb3[1] sda3[0]
510976 blocks super 1.0 level 5, 512k chunk, algorithm 2 [3/3] [UUU]
md126 : inactive sdb1[1](S) sda1[0](S) sdc1[3](S)
5614906368 blocks super 1.2
md127 : active raid5 sdc2[3] sdb2[1] sda2[0]
7883776 blocks super 1.2 level 5, 512k chunk, algorithm 2 [3/3] [UUU]
unused devices:
proses rebuild RAID sedang berlangsung, tunggu sampai selesai proses tersebut lalu booting kembali ke hardisk. Komputer sudah bisa digunakan seperti biasanya.