복구 테스트 (강제적으로 레이두1의 0마운트 해제 하자)
mdadm --manage /dev/md0 --fail /dev/sdb1
mdadm --manage /dev/md1 --fail /dev/sdb2
mdadm --manage /dev/md2 --fail /dev/sdb3
mdadm --manage /dev/md0 --remove /dev/sdb1
mdadm --manage /dev/md1 --remove /dev/sdb2
mdadm --manage /dev/md2 --remove /dev/sdb3
Shut down the system:
shutdown -h now
Then put in a new /dev/sdb drive (if you simulate a failure of /dev/sda, you should now put /dev/sdb in /dev/sda's place and connect the new HDD as/dev/sdb!) and boot the system. It should still start without problems.
Now run
cat /proc/mdstat
and you should see that we have a degraded array:
server1:~# cat /proc/mdstat
Personalities : [raid1]
md2 : active raid1 sda3[0]
4594496 blocks [2/1] [U_]
md1 : active raid1 sda2[0]
497920 blocks [2/1] [U_]
md0 : active raid1 sda1[0]
144448 blocks [2/1] [U_]
unused devices: <none>
server1:~#
The output of
fdisk -l
should look as follows:
server1:~# fdisk -l
Disk /dev/sda: 5368 MB, 5368709120 bytes
255 heads, 63 sectors/track, 652 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 18 144553+ fd Linux raid autodetect
/dev/sda2 19 80 498015 fd Linux raid autodetect
/dev/sda3 81 652 4594590 fd Linux raid autodetect
Disk /dev/sdb: 5368 MB, 5368709120 bytes
255 heads, 63 sectors/track, 652 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/sdb doesn't contain a valid partition table
Disk /dev/md0: 147 MB, 147914752 bytes
2 heads, 4 sectors/track, 36112 cylinders
Units = cylinders of 8 * 512 = 4096 bytes
Disk /dev/md0 doesn't contain a valid partition table
Disk /dev/md1: 509 MB, 509870080 bytes
2 heads, 4 sectors/track, 124480 cylinders
Units = cylinders of 8 * 512 = 4096 bytes
Disk /dev/md1 doesn't contain a valid partition table
Disk /dev/md2: 4704 MB, 4704763904 bytes
2 heads, 4 sectors/track, 1148624 cylinders
Units = cylinders of 8 * 512 = 4096 bytes
Disk /dev/md2 doesn't contain a valid partition table
server1:~#
Now we copy the partition table of /dev/sda to /dev/sdb:
sfdisk -d /dev/sda | sfdisk /dev/sdb
(If you get an error, you can try the --force option:
sfdisk -d /dev/sda | sfdisk --force /dev/sdb
)
server1:~# sfdisk -d /dev/sda | sfdisk /dev/sdb
Checking that no-one is using this disk right now ...
OK
Disk /dev/sdb: 652 cylinders, 255 heads, 63 sectors/track
sfdisk: ERROR: sector 0 does not have an msdos signature
/dev/sdb: unrecognized partition table type
Old situation:
No partitions found
New situation:
Units = sectors of 512 bytes, counting from 0
Device Boot Start End #sectors Id System
/dev/sdb1 * 63 289169 289107 fd Linux raid autodetect
/dev/sdb2 289170 1285199 996030 fd Linux raid autodetect
/dev/sdb3 1285200 10474379 9189180 fd Linux raid autodetect
/dev/sdb4 0 - 0 0 Empty
Successfully wrote the new partition table
Re-reading the partition table ...
If you created or changed a DOS partition, /dev/foo7, say, then use dd(1)
to zero the first 512 bytes: dd if=/dev/zero of=/dev/foo7 bs=512 count=1
(See fdisk(8).)
server1:~#
Afterwards we remove any remains of a previous RAID array from /dev/sdb...
mdadm --zero-superblock /dev/sdb1
mdadm --zero-superblock /dev/sdb2
mdadm --zero-superblock /dev/sdb3
... and add /dev/sdb to the RAID array:
mdadm -a /dev/md0 /dev/sdb1
mdadm -a /dev/md1 /dev/sdb2
mdadm -a /dev/md2 /dev/sdb3
Now take a look at
cat /proc/mdstat
server1:~# cat /proc/mdstat
Personalities : [raid1]
md2 : active raid1 sdb3[2] sda3[0]
4594496 blocks [2/1] [U_]
[======>..............] recovery = 30.8% (1416256/4594496) finish=0.6min speed=83309K/sec
md1 : active raid1 sdb2[1] sda2[0]
497920 blocks [2/2] [UU]
md0 : active raid1 sdb1[1] sda1[0]
144448 blocks [2/2] [UU]
unused devices: <none>
server1:~#
Wait until the synchronization has finished:
server1:~# cat /proc/mdstat
Personalities : [raid1]
md2 : active raid1 sdb3[1] sda3[0]
4594496 blocks [2/2] [UU]
md1 : active raid1 sdb2[1] sda2[0]
497920 blocks [2/2] [UU]
md0 : active raid1 sdb1[1] sda1[0]
144448 blocks [2/2] [UU]
unused devices: <none>
server1:~#
Then run
grub
and install the bootloader on both HDDs:
root (hd0,0)
setup (hd0)
root (hd1,0)
setup (hd1)
quit
That's it. You've just replaced a failed hard drive in your RAID1 array.
10 Links
• The Software-RAID Howto: http://tldp.org/HOWTO/Software-RAID-HOWTO.html
• Debian: http://www.debian.org
previous
up
How To Set Up Software RAID1 On A Running System (Incl. GRUB Configuration) (Debian Etch) - Page 3
6 Preparing GRUB 복구
Afterwards we must install the GRUB bootloader on the second hard drive /dev/sdb:
grub
On the GRUB shell, type in the following commands:
root (hd0,0)
grub> root (hd0,0)
Filesystem type is ext2fs, partition type 0x83
grub>
setup (hd0)
grub> setup (hd0)
Checking if "/boot/grub/stage1" exists... no
Checking if "/grub/stage1" exists... yes
Checking if "/grub/stage2" exists... yes
Checking if "/grub/e2fs_stage1_5" exists... yes
Running "embed /grub/e2fs_stage1_5 (hd0)"... 15 sectors are embedded.
succeeded
Running "install /grub/stage1 (hd0) (hd0)1+15 p (hd0,0)/grub/stage2 /grub/menu.lst"... succeeded
Done.
grub>
root (hd1,0)
grub> root (hd1,0)
Filesystem type is ext2fs, partition type 0xfd
grub>
setup (hd1)
grub> setup (hd1)
Checking if "/boot/grub/stage1" exists... no
Checking if "/grub/stage1" exists... yes
Checking if "/grub/stage2" exists... yes
Checking if "/grub/e2fs_stage1_5" exists... yes
Running "embed /grub/e2fs_stage1_5 (hd1)"... 15 sectors are embedded.
succeeded
Running "install /grub/stage1 (hd1) (hd1)1+15 p (hd1,0)/grub/stage2 /grub/menu.lst"... succeeded
Done.
grub>
quit
Now, back on the normal shell, we reboot the system and hope that it boots ok from our RAID arrays:
reboot
원본 위치 <http://www.howtoforge.com/software-raid1-grub-boot-debian-etch-p2>
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