MDADM - add non-boot, non-root partition to raid(mirror)

 

Assumptions:

partition on both disks already set and equal

 

  • create an array(for SWAP)
 

# mdadm --create /dev/md1 --level=mirror --raid-devices=2 /dev/sda2 /dev/sdb2

 

Continue creating array? y

check our new array

# mdadm --detail /dev/md1

/dev/md1:
Version : 1.2
Creation Time : Tue Dec 25 10:11:58 2012
Raid Level : raid1
Array Size : 15622116 (14.90 GiB 16.00 GB)
Used Dev Size : 15622116 (14.90 GiB 16.00 GB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent

Update Time : Tue Dec 25 10:11:58 2012
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0

Name : sec:1 (local to host sec)
UUID : 745325ec:bbac31fd:56475afa:528918ac
Events : 0

Number Major Minor RaidDevice State
0 8 2 0 active sync /dev/sda2
1 8 18 1 active sync /dev/sdb2

 

add this partition to mdadm.conf file so next reboot will be recognized

# mdadm -Es | grep :1 >> /etc/mdadm/mdadm.conf

 

 create swap

# mkswap -c /dev/md1

 enable swap(mount)

# swapon /dev/md1

 

 

 - before mounting swap

# free -m
total used free shared buffers cached
Mem: 16002 559 15443 0 2 142
-/+ buffers/cache: 414 15588
Swap: 0 0 0

  - after mounting swap

# free -m
total used free shared buffers cached
Mem: 16002 542 15460 0 3 144
-/+ buffers/cache: 395 15607
Swap: 15255 0 15255

 

 add swap partition to /etc/fstab (in my fstab file it looks like below)

# swap was on /dev/md1
UUID=da6ad2c4-9f38-4ffb-ba1e-2303649d075f none swap sw 0 0

  • create array(for /home)
 

# mdadm --create /dev/md2 --level=mirror --raid-devices=2 /dev/sda3 /dev/sdb3

mdadm: Note: this array has metadata at the start and
may not be suitable as a boot device. If you plan to
store '/boot' on this device please ensure that
your boot-loader understands md/v1.x metadata, or use
--metadata=0.90
Continue creating array?y

mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md2 started.

 

 disaplay all arrays

# mdadm -Es
ARRAY /dev/md/0 metadata=1.2 UUID=02b817b7:41dad749:67c03f7a:bfee433d name=sec:0
ARRAY /dev/md/1 metadata=1.2 UUID=745325ec:bbac31fd:56475afa:528918ac name=sec:1
ARRAY /dev/md/2 metadata=1.2 UUID=8e3c1dbb:6ff07a83:364a66a5:bd43c518 name=sec:2

add our new array(2) to mdadm.conf file

# mdadm -Es | grep :2 >> /etc/mdadm/mdadm.conf

 format /dev/md2

# mkfs -t ext3 -L /home /dev/md2
mke2fs 1.41.12 (17-May-2010)
Etykieta systemu plików=/home
Typ OS: Linux
Rozmiar bloku=4096 (log=2)
Rozmiar fragmentu=4096 (log=2)
Stride=0 bloków, szerokość Stripe=0 bloków
57024512 i-węzłów, 228076310 bloków
11403815 bloków (5.00%) zarezerwowanych dla superużytkownika
Pierwszy blok danych=0
Maksymalna liczba bloków systemu plików=4294967296
6961 grup bloków
32768 bloków w grupie, 32768 fragmentów w grupie
8192 i-węzłów w grupie
Kopie zapasowe superbloku zapisane w blokach:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,
102400000, 214990848

Zapis tablicy i-węzłów: 1252/6961
zakończono
Tworzenie kroniki (32768 bloków): wykonano
Zapis superbloków i podsumowania systemu plików: wykonano

Ten system plików będzie automatycznie sprawdzany co każde 34 montowań
lub co 180 dni, zależnie co nastąpi pierwsze. Można to zmienić poprzez
tune2fs -c lub -i.

 

check status of array md2

# mdadm --detail /dev/md2
/dev/md2:
Version : 1.2
Creation Time : Tue Dec 25 11:05:20 2012
Raid Level : raid1
Array Size : 912305240 (870.04 GiB 934.20 GB)
Used Dev Size : 912305240 (870.04 GiB 934.20 GB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent

Update Time : Tue Dec 25 11:12:49 2012
State : active, resyncing
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0

Rebuild Status : 3% complete

Name : sec:2 (local to host sec)
UUID : 8e3c1dbb:6ff07a83:364a66a5:bd43c518
Events : 1

Number Major Minor RaidDevice State
      0         8        3             0         active sync /dev/sda3
      1        1 8     19            1         active sync /dev/sdb3

 

 add /home to fstab

# blkid | grep md2
/dev/md2: LABEL="/home" UUID="785a8b54-46e1-4b8e-b2f9-e8e0eac0c37d" SEC_TYPE="ext2" TYPE="ext3"

# /home
UUID=785a8b54-46e1-4b8e-b2f9-e8e0eac0c37d /home ext3 nodev,nosuid,noexec,usrquota,grpquota 0 2

 

 mount /home

# mount /dev/md2
# df
System plików bl. 1K B użyte dostępne %uż. zamont. na
/dev/md0     48059200     3445756     42172132     8% /
tmpfs 8193516 0 8193516 0% /lib/init/rw
udev 8188492 144 8188348 1% /dev
tmpfs 8193516 0 8193516 0% /dev/shm
/dev/md2    897989168      204872   852169036   1%   /home

 

dzbanek 2012-12-25

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