md:
mdadm: 将任何块设备做成RAID
模式化的命令：
1.创建模式
-C 专用选项：
-l: 级别
-n #: 设备个数
-a {yes|no}: 是否自动为其创建设备文件
-c: CHUNK大小, 2^n，默认为64KB,最好为块的倍数 ,为了提高raid 0/5 的性能 mke2fs -E stride=16 -b 4096 /dev/md0
-x #: 指定空闲盘个数
3.管理模式
--add, --remove, --fail mdadm /dev/md# --fail /dev/sda7
4.监控模式
-F
5.增长模式
-G
6.装配模式
-A
查看RAID阵列的详细信息
mdadm -D /dev/md# --detail
停止阵列：
mdadm -S /dev/md# --stop
删除设备文件
rm /dev/md#
创建功能:
1.创建一个空间大小为6G的RAID0设备
RAID0 6G:
2: 3GB
首先创建2个3G大小的分区,并把类型调成read的类型
[email protected]_160_34_centos:~> fdisk /dev/xvdb
WARNING: DOS-compatible mode is deprecated. It‘s strongly recommended to
switch off the mode (command ‘c‘) and change display units to
sectors (command ‘u‘).
Command (m for help): p
Disk /dev/xvdb: 53.7 GB, 53687091200 bytes
255 heads, 63 sectors/track, 6527 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xc77f92d7
Device Boot Start End Blocks Id System
/dev/xvdb4 1 6527 52428096 5 Extended
/dev/xvdb5 1 262 2104452 83 Linux
/dev/xvdb6 263 655 3156741 83 Linux
/dev/xvdb7 656 1048 3156741 83 Linux
/dev/xvdb8 1049 1441 3156741 83 Linux
/dev/xvdb9 1442 1834 3156741 83 Linux
Command (m for help): d
Partition number (1-9): 4
Command (m for help): p
Disk /dev/xvdb: 53.7 GB, 53687091200 bytes
255 heads, 63 sectors/track, 6527 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xc77f92d7
Device Boot Start End Blocks Id System
Command (m for help): n
Command action
e extended
p primary partition (1-4)
e
Partition number (1-4): 4
First cylinder (1-6527, default 1):
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-6527, default 6527):
Using default value 6527
Command (m for help): p
Disk /dev/xvdb: 53.7 GB, 53687091200 bytes
255 heads, 63 sectors/track, 6527 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xc77f92d7
Device Boot Start End Blocks Id System
/dev/xvdb4 1 6527 52428096 5 Extended
Command (m for help): n
Command action
l logical (5 or over)
p primary partition (1-4)
l
First cylinder (1-6527, default 1):
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-6527, default 6527): +3G
Command (m for help): p
Disk /dev/xvdb: 53.7 GB, 53687091200 bytes
255 heads, 63 sectors/track, 6527 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xc77f92d7
Device Boot Start End Blocks Id System
/dev/xvdb4 1 6527 52428096 5 Extended
/dev/xvdb5 1 393 3156709+ 83 Linux
Command (m for help): n
Command action
l logical (5 or over)
p primary partition (1-4)
l
First cylinder (394-6527, default 394):
Using default value 394
Last cylinder, +cylinders or +size{K,M,G} (394-6527, default 6527): +3G
Command (m for help): p
Disk /dev/xvdb: 53.7 GB, 53687091200 bytes
255 heads, 63 sectors/track, 6527 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xc77f92d7
Device Boot Start End Blocks Id System
/dev/xvdb4 1 6527 52428096 5 Extended
/dev/xvdb5 1 393 3156709+ 83 Linux
/dev/xvdb6 394 786 3156741 83 Linux
Command (m for help): t
Partition number (1-6): 5
Hex code (type L to list codes): l
0 Empty 24 NEC DOS 81 Minix / old Lin bf Solaris
1 FAT12 39 Plan 9 82 Linux swap / So c1 DRDOS/sec (FAT-
2 XENIX root 3c PartitionMagic 83 Linux c4 DRDOS/sec (FAT-
3 XENIX usr 40 Venix 80286 84 OS/2 hidden C: c6 DRDOS/sec (FAT-
4 FAT16 <32M 41 PPC PReP Boot 85 Linux extended c7 Syrinx
5 Extended 42 SFS 86 NTFS volume set da Non-FS data
6 FAT16 4d QNX4.x 87 NTFS volume set db CP/M / CTOS / .
7 HPFS/NTFS 4e QNX4.x 2nd part 88 Linux plaintext de Dell Utility
8 AIX 4f QNX4.x 3rd part 8e Linux LVM df BootIt
9 AIX bootable 50 OnTrack DM 93 Amoeba e1 DOS access
a OS/2 Boot Manag 51 OnTrack DM6 Aux 94 Amoeba BBT e3 DOS R/O
b W95 FAT32 52 CP/M 9f BSD/OS e4 SpeedStor
c W95 FAT32 (LBA) 53 OnTrack DM6 Aux a0 IBM Thinkpad hi eb BeOS fs
e W95 FAT16 (LBA) 54 OnTrackDM6 a5 FreeBSD ee GPT
f W95 Ext‘d (LBA) 55 EZ-Drive a6 OpenBSD ef EFI (FAT-12/16/
10 OPUS 56 Golden Bow a7 NeXTSTEP f0 Linux/PA-RISC b
11 Hidden FAT12 5c Priam Edisk a8 Darwin UFS f1 SpeedStor
12 Compaq diagnost 61 SpeedStor a9 NetBSD f4 SpeedStor
14 Hidden FAT16 <3 63 GNU HURD or Sys ab Darwin boot f2 DOS secondary
16 Hidden FAT16 64 Novell Netware af HFS / HFS+ fb VMware VMFS
17 Hidden HPFS/NTF 65 Novell Netware b7 BSDI fs fc VMware VMKCORE
18 AST SmartSleep 70 DiskSecure Mult b8 BSDI swap fd Linux raid auto
1b Hidden W95 FAT3 75 PC/IX bb Boot Wizard hid fe LANstep
1c Hidden W95 FAT3 80 Old Minix be Solaris boot ff BBT
1e Hidden W95 FAT1
Hex code (type L to list codes): fd
Changed system type of partition 5 to fd (Linux raid autodetect)
Command (m for help): t
Partition number (1-6): 6
Hex code (type L to list codes): fd
Changed system type of partition 6 to fd (Linux raid autodetect)
Command (m for help): p
Disk /dev/xvdb: 53.7 GB, 53687091200 bytes
255 heads, 63 sectors/track, 6527 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xc77f92d7
Device Boot Start End Blocks Id System
/dev/xvdb4 1 6527 52428096 5 Extended
/dev/xvdb5 1 393 3156709+ fd Linux raid autodetect
/dev/xvdb6 394 786 3156741 fd Linux raid autodetect
确认一下分区已被内核识别
[email protected]_160_34_centos:~> cat /proc/partitions major minor #blocks name 202 0 8388608 xvda 202 1 8385898 xvda1 202 16 52428800 xvdb 202 20 1 xvdb4 202 21 3156709 xvdb5 202 22 3156741 xvdb6 202 32 2097152 xvdc
执行创建命令
[email protected]_160_34_centos:~> mdadm -C /dev/md0 -a yes -l 0 -n 2 /dev/xvdb{5,6}
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md0 started.
我们 看一下 /proc/mdstat 文件, 这个文件里面记录着系统中所有启动在的raid 设备
[email protected]_160_34_centos:~> cat /proc/mdstat
Personalities : [raid0]
md0 : active raid0 xvdb6[1] xvdb5[0]
6310912 blocks super 1.2 512k chunks
unused devices: <none>
我们把它们格式化,
[email protected]_160_34_centos:~> mke2fs -j /dev/md0
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=128 blocks, Stripe width=256 blocks
395136 inodes, 1577728 blocks
78886 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=1619001344
49 block groups
32768 blocks per group, 32768 fragments per group
8064 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 37 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
然后挂载到mnt下
[email protected]_160_34_centos:~> mount /dev/md0 /mnt/ [email protected]_160_34_centos:~> ll /mnt/ total 16 drwx------ 2 root root 16384 Nov 21 15:30 lost+found
到此这个 raid 成功可以使用
创建1G的 raid1
我们首先创建2个1G的分区,并调整它的类型
[email protected]_160_34_centos:~> fdisk /dev/xvdb
WARNING: DOS-compatible mode is deprecated. It‘s strongly recommended to
switch off the mode (command ‘c‘) and change display units to
sectors (command ‘u‘).
Command (m for help): p
Disk /dev/xvdb: 53.7 GB, 53687091200 bytes
255 heads, 63 sectors/track, 6527 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xc77f92d7
Device Boot Start End Blocks Id System
/dev/xvdb4 1 6527 52428096 5 Extended
/dev/xvdb5 1 393 3156709+ fd Linux raid autodetect
/dev/xvdb6 394 786 3156741 fd Linux raid autodetect
Command (m for help): n
Command action
l logical (5 or over)
p primary partition (1-4)
l
First cylinder (787-6527, default 787):
Using default value 787
Last cylinder, +cylinders or +size{K,M,G} (787-6527, default 6527): +1G
Command (m for help): n
Command action
l logical (5 or over)
p primary partition (1-4)
l
First cylinder (919-6527, default 919):
Using default value 919
Last cylinder, +cylinders or +size{K,M,G} (919-6527, default 6527): +1G
Command (m for help): p
Disk /dev/xvdb: 53.7 GB, 53687091200 bytes
255 heads, 63 sectors/track, 6527 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xc77f92d7
Device Boot Start End Blocks Id System
/dev/xvdb4 1 6527 52428096 5 Extended
/dev/xvdb5 1 393 3156709+ fd Linux raid autodetect
/dev/xvdb6 394 786 3156741 fd Linux raid autodetect
/dev/xvdb7 787 918 1060258+ 83 Linux
/dev/xvdb8 919 1050 1060258+ 83 Linux
Command (m for help): t
Partition number (1-8): 7
Hex code (type L to list codes): fd
Changed system type of partition 7 to fd (Linux raid autodetect)
Command (m for help): t
Partition number (1-8): 8
Hex code (type L to list codes): fd
Changed system type of partition 8 to fd (Linux raid autodetect)
Command (m for help): p
Disk /dev/xvdb: 53.7 GB, 53687091200 bytes
255 heads, 63 sectors/track, 6527 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xc77f92d7
Device Boot Start End Blocks Id System
/dev/xvdb4 1 6527 52428096 5 Extended
/dev/xvdb5 1 393 3156709+ fd Linux raid autodetect
/dev/xvdb6 394 786 3156741 fd Linux raid autodetect
/dev/xvdb7 787 918 1060258+ fd Linux raid autodetect
/dev/xvdb8 919 1050 1060258+ 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: Device or resource busy.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe(8) or kpartx(8)
Syncing disks.
确保内核已经识别了我们的分区,如果没有执行 partx -a /dev/xvdb 来识别(可能需要umount 该盘其他挂载点) ,
[email protected]_160_34_centos:~> mdadm -C /dev/md1 -a yes -l 1 -n 2 /dev/xvdb{7,8}
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
执行创建命令
[email protected]_160_34_centos:~> mdadm -C /dev/md1 -a yes -l 1 -n 2 /dev/xvdb{7,8}
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/md1 started.
执行的时候它会问你是否需要创建, 这个是毫无疑问的.
我们查看一下它的状态
[email protected]_160_34_centos:~> cat /proc/mdstat
Personalities : [raid0] [raid1]
md1 : active raid1 xvdb8[1] xvdb7[0]
1059222 blocks super 1.2 [2/2] [UU]
[==========>..........] resync = 54.6% (579524/1059222) finish=0.0min speed=144881K/sec
md0 : active raid0 xvdb6[1] xvdb5[0]
6310912 blocks super 1.2 512k chunks
unused devices: <none>
格式化,
[email protected]_160_34_centos:~> mke2fs -j /dev/md1
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
66240 inodes, 264805 blocks
13240 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=272629760
9 block groups
32768 blocks per group, 32768 fragments per group
7360 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376
Writing inode tables: done
Creating journal (8192 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.
挂载
[email protected]_160_34_centos:~> mount /dev/md1 /storage/ [email protected]_160_34_centos:~> ll /storage/ total 16 drwx------ 2 root root 16384 Nov 21 15:51 lost+found
我们查看一下这个阵列的属性:
[email protected]_160_34_centos:~> mdadm -D /dev/md1
/dev/md1:
Version : 1.2
Creation Time : Fri Nov 21 15:48:21 2014
Raid Level : raid1
Array Size : 1059222 (1034.57 MiB 1084.64 MB)
Used Dev Size : 1059222 (1034.57 MiB 1084.64 MB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent
Update Time : Fri Nov 21 15:53:44 2014
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
Name : VM_160_34_centos:1 (local to host VM_160_34_centos)
UUID : 4e1ea263:6297d669:9d5877af:6e5fc1e0
Events : 17
Number Major Minor RaidDevice State
0 202 23 0 active sync /dev/xvdb7
1 202 24 1 active sync /dev/xvdb8
然后拷贝个文件进去,模拟损坏一个设备,文件照常访问
[email protected]_160_34_centos:~> mdadm -D /dev/md1
/dev/md1:
Version : 1.2
Creation Time : Fri Nov 21 15:48:21 2014
Raid Level : raid1
Array Size : 1059222 (1034.57 MiB 1084.64 MB)
Used Dev Size : 1059222 (1034.57 MiB 1084.64 MB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent
Update Time : Fri Nov 21 15:57:29 2014
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
Name : VM_160_34_centos:1 (local to host VM_160_34_centos)
UUID : 4e1ea263:6297d669:9d5877af:6e5fc1e0
Events : 17
Number Major Minor RaidDevice State
0 202 23 0 active sync /dev/xvdb7
1 202 24 1 active sync /dev/xvdb8
[email protected]_160_34_centos:~> mdadm /dev/md1 -f /dev/xvdb8
mdadm: set /dev/xvdb8 faulty in /dev/md1
[email protected]_160_34_centos:~> mdadm -D /dev/md1
/dev/md1:
Version : 1.2
Creation Time : Fri Nov 21 15:48:21 2014
Raid Level : raid1
Array Size : 1059222 (1034.57 MiB 1084.64 MB)
Used Dev Size : 1059222 (1034.57 MiB 1084.64 MB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent
Update Time : Fri Nov 21 15:59:05 2014
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 1
Spare Devices : 0
Name : VM_160_34_centos:1 (local to host VM_160_34_centos)
UUID : 4e1ea263:6297d669:9d5877af:6e5fc1e0
Events : 18
Number Major Minor RaidDevice State
0 202 23 0 active sync /dev/xvdb7
1 0 0 1 removed
1 202 24 - faulty spare /dev/xvdb8
[email protected]_160_34_centos:~> cat /storage/passwd
root:x:0:0:root:/root:/bin/bash
bin:x:1:1:bin:/bin:/sbin/nologin
daemon:x:2:2:daemon:/sbin:/sbin/nologin
adm:x:3:4:adm:/var/adm:/sbin/nologin
lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
sync:x:5:0:sync:/sbin:/bin/sync
shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
halt:x:7:0:halt:/sbin:/sbin/halt
mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
uucp:x:10:14:uucp:/var/spool/uucp:/sbin/nologin
operator:x:11:0:operator:/root:/sbin/nologin
games:x:12:100:games:/usr/games:/sbin/nologin
gopher:x:13:30:gopher:/var/gopher:/sbin/nologin
ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin
nobody:x:99:99:Nobody:/:/sbin/nologin
dbus:x:81:81:System message bus:/:/sbin/nologin
vcsa:x:69:69:virtual console memory owner:/dev:/sbin/nologin
abrt:x:173:173::/etc/abrt:/sbin/nologin
haldaemon:x:68:68:HAL daemon:/:/sbin/nologin
ntp:x:38:38::/etc/ntp:/sbin/nologin
saslauth:x:499:76:"Saslauthd user":/var/empty/saslauth:/sbin/nologin
postfix:x:89:89::/var/spool/postfix:/sbin/nologin
sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin
tcpdump:x:72:72::/:/sbin/nologin
nscd:x:28:28:NSCD Daemon:/:/sbin/nologin
nslcd:x:65:55:LDAP Client User:/:/sbin/nologin
dd:x:500:500::/home/dd:/bin/bash
mysql:x:501:501::/home/mysql:/sbin/nologin
vsftpd:x:502:502::/home/vsftpd:/sbin/nologin
www:x:503:503::/storage/www:/sbin/nologin
hadoop:x:504:504::/home/hadoop:/bin/bash
我们替换1一个好的设备进去
[email protected]_160_34_centos:~> mdadm -D /dev/md1
/dev/md1:
Version : 1.2
Creation Time : Fri Nov 21 15:48:21 2014
Raid Level : raid1
Array Size : 1059222 (1034.57 MiB 1084.64 MB)
Used Dev Size : 1059222 (1034.57 MiB 1084.64 MB)
Raid Devices : 2
Total Devices : 1
Persistence : Superblock is persistent
Update Time : Fri Nov 21 16:01:42 2014
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
Name : VM_160_34_centos:1 (local to host VM_160_34_centos)
UUID : 4e1ea263:6297d669:9d5877af:6e5fc1e0
Events : 25
Number Major Minor RaidDevice State
0 202 23 0 active sync /dev/xvdb7
1 0 0 1 removed
添加 xvdb 9
[email protected]_160_34_centos:~> mdadm /dev/md1 -a /dev/xvdb9
mdadm: added /dev/xvdb9
[email protected]_160_34_centos:~> mdadm -D /dev/md1
/dev/md1:
Version : 1.2
Creation Time : Fri Nov 21 15:48:21 2014
Raid Level : raid1
Array Size : 1059222 (1034.57 MiB 1084.64 MB)
Used Dev Size : 1059222 (1034.57 MiB 1084.64 MB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent
Update Time : Fri Nov 21 16:04:46 2014
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
Name : VM_160_34_centos:1 (local to host VM_160_34_centos)
UUID : 4e1ea263:6297d669:9d5877af:6e5fc1e0
Events : 46
Number Major Minor RaidDevice State
0 202 23 0 active sync /dev/xvdb7
2 202 25 1 active sync /dev/xvdb9
如果我们再 raid 中添加了3个设备, 那么空余那个会在其中一个设备坏了的之后制动替换掉坏掉的那个.
为了方便以后装载,我们把配置写入配置文件
将当前RAID信息保存至配置文件，以便以后进行装配： mdamd -D --scan > /etc/mdadm.conf
创建一个 2G的 raid5(只要有冗余的都支持空闲盘,所以我们需要4个1G的设备,跟raid1的用法是一样的)
时间： 2024-10-08 00:21:36