MDADM (리눅스RAID) 사용하기
// mdadm 명령으로 직접 리눅스 머신상에서 구현해 보았습니다.
[root@ruset root]# rpm -qi mdadm
Name : mdadm Relocations: (not relocateable)
Version : 1.0.1 Vendor: Red Hat, Inc.
Release : 1 Build Date: 2003년 01월 29일 (수)
오전 05시 03분 32초
Install Date: 2006년 09월 14일 (목) 오후 12시 06분 54초 Build Host:
stripples.devel.redhat.com
Group : 시스템 환경/기반 Source RPM: mdadm-1.0.1-1.src.rpm
Size : 117762 License: GPL
Signature : DSA/SHA1, 2003년 02월 24일 (월) 오후 03시 36분 13초, Key ID
219180cddb42a60e
Packager : Red Hat, Inc. <http://bugzilla.redhat.com/bugzilla>
URL : http://www.cse.unsw.edu.au/~neilb/source/mdadm/
Summary : mdadm는 리눅스 md 장치 (소프트웨어 RAID 배열)을 제어합니다.
Description :
mdadm 프로그램은 Linux MD (소프트웨어 RAID) 장치를 만들고, 관리하며 감시하는데
사용됩니다. 따라서 raidtools 패키지와 유사한 기능을 제공합니다.
그러나 mdadm은 단독 프로그램이기 때문에, 설정 파일을 사용하여 일부 작업을
수행하는데 도움을 받을 수는 있지만 설정 파일 없이도 거의 모든 기능을
수행할 수 있습니다.
==> mdadm 패키지 정보
[root@ruset root]# rpm -ql mdadm
/etc/mdadm.conf
/etc/rc.d/init.d/mdmonitor
/sbin/mdadm
/usr/share/doc/mdadm-1.0.1
/usr/share/doc/mdadm-1.0.1/COPYING
/usr/share/doc/mdadm-1.0.1/ChangeLog
/usr/share/doc/mdadm-1.0.1/TODO
/usr/share/doc/mdadm-1.0.1/mdadm.conf-example
/usr/share/man/man4/md.4.gz
/usr/share/man/man5/mdadm.conf.5.gz
/usr/share/man/man8/mdadm.8.gz
[root@redhat root]#
==> 각종 설정파일들. 설정파일을 보니 raid-tool과 비슷하게 mdadm.conf파일이 있다. 설정파일로도 구성할 수 있는듯 한데… 이 설정파일을 통한 구성은 찾아보기 힘들었다..
[root@ruset ~]# fdisk -l
Disk /dev/hda: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/hda1 * 1 4700 37752718+ 7 HPFS/NTFS
/dev/hda2 4701 19456 118527570 f Win95 Ext’d (LBA)
/dev/hda5 4701 11074 51199123+ 7 HPFS/NTFS
/dev/hda6 11075 11087 104391 83 Linux
/dev/hda7 11088 12362 10241406 83 Linux
/dev/hda8 12363 12884 4192933+ 82 Linux swap
==> 현재 파티션 구성
[root@ruset ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/hda7 9.7G 4.1G 5.2G 45% /
/dev/hda6 99M 15M 80M 16% /boot
none 1003M 0 1003M 0% /dev/shm
==> 현재 mount 정보
[root@ruset ~]# fdisk /dev/hda
The number of cylinders for this disk is set to 19457.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
(e.g., DOS FDISK, OS/2 FDISK)
Command (m for help): p
Disk /dev/hda: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/hda1 * 1 4700 37752718+ 7 HPFS/NTFS
/dev/hda2 4701 19456 118527570 f Win95 Ext’d (LBA)
/dev/hda5 4701 11074 51199123+ 7 HPFS/NTFS
/dev/hda6 11075 11087 104391 83 Linux
/dev/hda7 11088 12362 10241406 83 Linux
/dev/hda8 12363 12884 4192933+ 82 Linux swap
Command (m for help): n
Command action
l logical (5 or over)
p primary partition (1-4)
l
First cylinder (12885-19456, default 12885):
Using default value 12885
Last cylinder or +size or +sizeM or +sizeK (12885-19456, default 19456): +1000m
Command (m for help): p
Disk /dev/hda: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/hda1 * 1 4700 37752718+ 7 HPFS/NTFS
/dev/hda2 4701 19456 118527570 f Win95 Ext’d (LBA)
/dev/hda5 4701 11074 51199123+ 7 HPFS/NTFS
/dev/hda6 11075 11087 104391 83 Linux
/dev/hda7 11088 12362 10241406 83 Linux
/dev/hda8 12363 12884 4192933+ 82 Linux swap
/dev/hda9 12885 13007 987966 83 Linux
Command (m for help): n
Command action
l logical (5 or over)
p primary partition (1-4)
l
First cylinder (13008-19456, default 13008):
Using default value 13008
Last cylinder or +size or +sizeM or +sizeK (13008-19456, default 19456): +1000m
Command (m for help): p
Disk /dev/hda: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/hda1 * 1 4700 37752718+ 7 HPFS/NTFS
/dev/hda2 4701 19456 118527570 f Win95 Ext’d (LBA)
/dev/hda5 4701 11074 51199123+ 7 HPFS/NTFS
/dev/hda6 11075 11087 104391 83 Linux
/dev/hda7 11088 12362 10241406 83 Linux
/dev/hda8 12363 12884 4192933+ 82 Linux swap
/dev/hda9 12885 13007 987966 83 Linux
/dev/hda10 13008 13130 987966 83 Linux
Command (m for help): t
Partition number (1-10): 9
Hex code (type L to list codes): fd
Changed system type of partition 9 to fd (Linux raid autodetect)
Command (m for help): t
Partition number (1-10): 10
Hex code (type L to list codes): fd
Changed system type of partition 10 to fd (Linux raid autodetect)
Command (m for help): p
Disk /dev/hda: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/hda1 * 1 4700 37752718+ 7 HPFS/NTFS
/dev/hda2 4701 19456 118527570 f Win95 Ext’d (LBA)
/dev/hda5 4701 11074 51199123+ 7 HPFS/NTFS
/dev/hda6 11075 11087 104391 83 Linux
/dev/hda7 11088 12362 10241406 83 Linux
/dev/hda8 12363 12884 4192933+ 82 Linux swap
/dev/hda9 12885 13007 987966 fd Linux raid autodetect
/dev/hda10 13008 13130 987966 fd Linux raid autodetect
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
WARNING: Re-reading the partition table failed with error 16: 장치나 자원이 동작 중.
The kernel still uses the old table.
The new table will be used at the next reboot.
Syncing disks.
[root@ruset ~]# reboot
==> 1기가로 파티션을 2개 구성한후 재부팅을 한다.
[root@ruset root]# fdisk -l
Disk /dev/hda: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/hda1 * 1 4700 37752718+ 7 HPFS/NTFS
/dev/hda2 4701 19456 118527570 f Win95 Ext’d (LBA)
/dev/hda5 4701 11074 51199123+ 7 HPFS/NTFS
/dev/hda6 11075 11087 104391 83 Linux
/dev/hda7 11088 12362 10241406 83 Linux
/dev/hda8 12363 12884 4192933+ 82 Linux swap
/dev/hda9 12885 13007 987966 fd Linux raid autodetect
/dev/hda10 13008 13130 987966 fd Linux raid autodetect
[root@redhat root]# mdadm -C /dev/md0 -l 1 -n 2 /dev/hda9 /dev/hda10
mdadm: /dev/hda9 appears to contain an ext2fs file system
size=987840K mtime=Fri Oct 20 17:32:33 2006
mdadm: /dev/hda9 appear to be part of a raid array:
level=1 devices=2 ctime=Tue Oct 17 15:33:51 2006
mdadm: /dev/hda10 appears to contain an ext2fs file system
size=987840K mtime=Fri Oct 20 17:32:33 2006
mdadm: /dev/hda10 appear to be part of a raid array:
level=1 devices=2 ctime=Tue Oct 17 15:33:51 2006
Continue creating array? y
mdadm: array /dev/md0 started.
==> mdadm 명령으로 raid를 구성한다. -l은 raid level, -n은 디바이스 갯수. hda9와 hda10이 예전에 meta정보를 포함하고 있어서 강제로 구성해준다.
[root@redhat root]# more /proc/mdstat
Personalities : [raid1]
read_ahead 1024 sectors
Event: 1
md0 : active raid1 hda10[1] hda9[0]
987840 blocks [2/2] [UU]
[>………………..] resync = 0.6% (6848/987840) finish=9.4min
speed=1712K/sec
unused devices:
==> resync 하는 중…
[root@redhat root]# mkfs.ext3 /dev/md0
mke2fs 1.32 (09-Nov-2002)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
123648 inodes, 246960 blocks
12348 blocks (5.00%) reserved for the super user
First data block=0
8 block groups
32768 blocks per group, 32768 fragments per group
15456 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376
Writing inode tables: done
Creating journal (4096 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 25 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
==> ext3파일시스템으로 구성해준다.
[root@redhat root]# vi /etc/fstab
#device name mount point file option
dump,fsck
LABEL=/ / ext3 defaults 1 1
LABEL=/boot /boot ext3 defaults 1 2
none /dev/pts devpts gid=5,mode=620 0 0
none /proc proc defaults 0 0
none /dev/shm tmpfs defaults 0 0
/dev/hda8 swap swap defaults 0 0
/dev/fd0 /mnt/floppy auto noauto,owner,kudzu 0 0
/dev/cdrom /mnt/cdrom udf,iso9660
noauto,owner,kudzu,ro 0 0
/dev/md0 /mdadm ext3 defaults 1 2
==> vi 편집기로 md정보를 기입해준다.
[root@redhat root]# cat /etc/fstab
#device name mount point file option
dump,fsck
LABEL=/ / ext3 defaults 1 1
LABEL=/boot /boot ext3 defaults 1 2
none /dev/pts devpts gid=5,mode=620 0 0
none /proc proc defaults 0 0
none /dev/shm tmpfs defaults 0 0
/dev/hda8 swap swap defaults 0 0
/dev/fd0 /mnt/floppy auto noauto,owner,kudzu 0 0
/dev/cdrom /mnt/cdrom udf,iso9660
noauto,owner,kudzu,ro 0 0
/dev/md0 /mdadm ext3 defaults 1 2
[root@redhat root]# mount -a
==> mount해준다.
[root@redhat root]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/hda7 9.7G 4.1G 5.2G 45% /
/dev/hda6 99M 15M 80M 16% /boot
none 1003M 0 1003M 0% /dev/shm
/dev/md0 950M 17M 886M 2% /mdadm
==> 정상적으로 mount된것을 볼 수가 있다.
[root@ruset root]# mdadm –detail /dev/md0
/dev/md0:
Version : 00.90.00
Creation Time : Fri Oct 20 17:45:41 2006
Raid Level : raid1
Array Size : 987840 (964.69 MiB 1011.55 MB)
Device Size : 987840 (964.69 MiB 1011.55 MB)
Raid Devices : 2
Total Devices : 2
Preferred Minor : 0
Persistence : Superblock is persistent
Update Time : Fri Oct 20 17:45:41 2006
State : dirty, no-errors
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
Number Major Minor RaidDevice State
0 3 9 0 active sync /dev/hda9
1 3 10 1 active sync /dev/hda10
UUID : 6e1e09ec:619f9d64:acd8d6b1:b4b7ff66
==> –detail 옵션으로 어떻게 구성되었는지 확인한다.
[root@redhat root]# more /proc/mdstat
Personalities : [raid1]
read_ahead 1024 sectors
Event: 1
md0 : active raid1 hda10[1] hda9[0]
987840 blocks [2/2] [UU]
unused devices:
[root@ruset root]#
==> resync완료!…md 구성이 정말 간단해졌다;
