RAID&LVM
RAID诞生原因
什么是RAID？
在计算机发展初期，单独的“大容量”磁盘价格十分昂贵。为了将廉价的多个小磁盘进行有机组合，使其容量和性能超过一只昂贵的大磁盘，1987年，三位加州大学伯克利分校的三位工程师Patterson、Gibson和Katz发表了题为《A Case of Redundant Array of Inexpensive Disks》的论文。
早期RAID叫做廉价磁盘冗余阵列，但在真正的生产环境实现过程中，发现廉价的磁盘已经体现不出RAID的技术优势了，后面就将Inexpensive改为Independent。所以现在RAID被称为独立磁盘冗余阵列。
RAID目前已成长为行业的事实标准。
RAID的核心思想----条带化（stripe）
对于组成RAID的设备，在CPU看来不是单独的多个磁盘，而是RAID将底层的多块存储设备组合起来对外输出成的一个设备。我们知道对于磁盘来说存储数据的单元是扇区（sector），对于文件系统来说存储数据的单元是数据块（block）,而对于这种RAID设备存储数据的单元叫做条带（strip）。在对RAID设备进行存储数据的时候并不是一个扇区或者一个数据块来存储的，而是将RAID设备下的磁盘分割为一个一个存储单元（strip），每个存储单元在每个磁盘的位置是对齐的，这种在我们看来就像一条一条的被称作条带（stripe）。
条带化
几个名词：
Strip：一块磁盘内连续编址的存储块，即为RAID定义的存储单元
Stripe：RAID中所有磁盘里对齐的Strip
Stripe depth：条带大小，及Strip的大小
Stripe width：RAID中的磁盘数
Stripe size：一个条带的大小，其值为Stripe depth * Stripe width
RAID的冗余技术
为了保证RAID中数据的可靠性，需要对数据进行冗余存储。RAID提供了两种冗余技术：镜像和校验码。
镜像
其原理是把一个磁盘的数据镜像到另一个磁盘上，即在写入一块磁盘的同时，会将数据同时存入另一块磁盘上。当其中一块磁盘损坏或数据丢失时，数据还可以从镜像中获取数据，以保证数据的可靠性。
校验码：
其原理为使用独立磁盘或采用分布式的方法使用校验码对条带（stripe）中的数据生成校验码，当条带中的某块磁盘数据丢失时，可以通过该条带剩余数据和校验码反推出丢失的数据，以此来保证数据的可靠性。
RAID的级别：
根据磁盘组织方式的不同，RAID有级别的划分，叫做RAID level。级别仅代表磁盘组织方式不同，没有上下之分。
RAID 0
RAID 0只是单纯的将磁盘组合起来，以成倍的提高磁盘的性能和容量，但是RAID 0没有提供冗余能力。其缺点为只要其中一块磁盘出现故障则整个阵列不可用，且磁盘数越多，故障率越高。
RAID 1
RAID 1称为磁盘镜像，所以其采用镜像的方式保证数据可靠性。由于所有数据需要镜像保存，故其磁盘利用率为50%。
RAID 2
RAID 2（带汉明码校验）。其数据分散为位或块，加入汉明码，间隔写入到磁盘阵列的每个磁盘中。商业环境极少使用。
RAID 3
RAID 3（带奇偶校验的并行传送），需要一块独立的磁盘用于校验。数据块分为小的块并行传输到每个磁盘上，同时采用奇偶校验将校验数据存放到用的校验磁盘上。
RAID 4
RAID 4（带奇偶校验码的独立磁盘结构），RAID 4跟RAID 3十分相似，它采用独立存取方式，将条带由RAID 3的小数据块改为更大的数据块，这是RAID 4和RAID 3最大的不同。
RAID 4和RAID 3这两种结构，由于每次存储数据及写入操作都需要计算校验码并存入校验盘中，故其写性能将会是其瓶颈。读操作不涉及校验盘，因而读性能会得到极大提升。
RAID 5
RAID 5（分布式奇偶校验的独立磁盘结构）。RAID 5不单独指定校验盘，而是所有磁盘上交叉存储数据和校验信息。RAID 5比之于RAID 4而言，由于其并不指定独立的校验盘，而是所有磁盘都参与校验信息，故而其读写性能均能得到提高。
RAID 6
对于RAID 5来说，当同一条带（stripe）上的一块磁盘上数据损坏时，可以通过该条带其余数据和该条带的校验码反推出损坏的数据，以保证其可靠性。但是当出现两块磁盘同时损坏时，那么就绝对无法恢复数据了。为了进一步确保数据的可靠性，在RAID 5的基础上扩展出RAID 6，它采用了2块磁盘用于校验盘，并允许最大两块盘的数据损毁。下图为RAID 6 P+Q模式
RAID 01
RAID 0和RAID 1的组合。先将磁盘分为两部分，每个部分先做RAID 0，再将这两个部分做RAID 1。
RAID 10
RAID 0和RAID 的组合。先将磁盘分为两部分，每个部分先做RAID 1，再将这两个部分做RAID 0。
RAID 01和RAID 10的比较
RAID 10实际优于RAID 01。为什么这么说呢，在磁盘正常时，两者并无差别，且均能提供N块磁盘的冗余。可是当一块磁盘出现故障不可用时，情况就会有所不同。
以上图为例，假如Disk 0发生故障，那么对于RAID 01或者RAID 10最多在提供一块磁盘的冗余。
RAID 10比RAID 01更可靠。
对于RAID 01由于Disk0损坏，且左边的为RAID 0，对于RAID 0来说其内部磁盘损坏一块，则整个RAID 0将不可用，故左边的RAID 0已不可用。因此只要右边RAID 0中Disk 2或3损坏一块，那么右边的RAID 0也将不可用，导致整个RAID 01不可用。其故障率为2/3，及再坏一块磁盘时有2/3概率导致整个阵列不可用。
对于RAID 10来说，及时Disk 0损坏，左边的RAID 1也将可用，当再出现一块磁盘故障时，只要不是Disk 1那么整个RAID 10都将是可用的。其故障率为1/3。
RAID 10比RAID 01读性能更高。
对于RAID 01读取数据只能通过Disk 2和Disk 3两块盘，而RAID 10则可以通过Disk 1、Disk 2和Disk 3三块盘，因而RAID 10比RAID 01此时读性能更高。
软RAID
需要内核中支持md（multi disks）的模块，通过软件的方式将磁盘或分区模拟成RAID供上层识别。这种RAID对于用户空间看来是个RAID设备，而对内核来说还是独立的磁盘或分区。软RAID又叫逻辑RAID。软RAID创建为在/dev下以md开头命名的设备文件，如md0，此处的md0并不代表RAID级别。
命令mdadm
mdadm：将任何块设备做成RAID，及时两个分区也可组成RAID
模式化的命令：
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64K
-x：指定空闲盘个数
管理模式
--add,--remove, --fail
mdadm /dev/md# --fail /dev/sda7
监控模式
-F
增长模式
-G
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
cat /proc/mdstat
watch：周期性地执行指定命令，并以全屏方式显示结果
-n #:指定周期长度，单位为秒，默认为2
格式：watch -n # 'COMMAND'
创建一个2G的RAID 0：
1）创建两个分区/dev/sdb4 /dev/sd5，且将其设置为fd格式
[[email protected] ~]# fdisk /dev/sdb
The number of cylinders for this disk is set to 2610.
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/sdb: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 7 56196 83 Linux
/dev/sdb2 8 10 24097+ 83 Linux
/dev/sdb3 11 23 104422+ 83 Linux
/dev/sdb4 24 2610 20780077+ 5 Extended
Command (m for help): n
First cylinder (24-2610, default 24):
Using default value 24
Last cylinder or +size or +sizeM or +sizeK (24-2610, default 2610): +1G
Command (m for help): n
First cylinder (147-2610, default 147):
Using default value 147
Last cylinder or +size or +sizeM or +sizeK (147-2610, default 2610): +1G
Command (m for help): p
Disk /dev/sdb: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 7 56196 83 Linux
/dev/sdb2 8 10 24097+ 83 Linux
/dev/sdb3 11 23 104422+ 83 Linux
/dev/sdb4 24 2610 20780077+ 5 Extended
/dev/sdb5 24 146 987966 83 Linux
/dev/sdb6 147 269 987966 83 Linux
Command (m for help): t
Partition number (1-6): 5
Hex code (type L to list codes): L
0 Empty 1e Hidden W95 FAT1 80 Old Minix bf Solaris
1 FAT12 24 NEC DOS 81 Minix / old Lin c1 DRDOS/sec (FAT-
2 XENIX root 39 Plan 9 82 Linux swap / So c4 DRDOS/sec (FAT-
3 XENIX usr 3c PartitionMagic 83 Linux c6 DRDOS/sec (FAT-
4 FAT16 <32M 40 Venix 80286 84 OS/2 hidden C: c7 Syrinx
5 Extended 41 PPC PReP Boot 85 Linux extended da Non-FS data
6 FAT16 42 SFS 86 NTFS volume set db CP/M / CTOS / .
7 HPFS/NTFS 4d QNX4.x 87 NTFS volume set de Dell Utility
8 AIX 4e QNX4.x 2nd part 88 Linux plaintext df BootIt
9 AIX bootable 4f QNX4.x 3rd part 8e Linux LVM e1 DOS access
a OS/2 Boot Manag 50 OnTrack DM 93 Amoeba e3 DOS R/O
b W95 FAT32 51 OnTrack DM6 Aux 94 Amoeba BBT e4 SpeedStor
c W95 FAT32 (LBA) 52 CP/M 9f BSD/OS eb BeOS fs
e W95 FAT16 (LBA) 53 OnTrack DM6 Aux a0 IBM Thinkpad hi ee EFI GPT
f W95 Ext'd (LBA) 54 OnTrackDM6 a5 FreeBSD ef EFI (FAT-12/16/
10 OPUS 55 EZ-Drive a6 OpenBSD f0 Linux/PA-RISC b
11 Hidden FAT12 56 Golden Bow a7 NeXTSTEP f1 SpeedStor
12 Compaq diagnost 5c Priam Edisk a8 Darwin UFS f4 SpeedStor
14 Hidden FAT16 <3 61 SpeedStor a9 NetBSD f2 DOS secondary
16 Hidden FAT16 63 GNU HURD or Sys ab Darwin boot fb VMware VMFS
17 Hidden HPFS/NTF 64 Novell Netware b7 BSDI fs fc VMware VMKCORE
18 AST SmartSleep 65 Novell Netware b8 BSDI swap fd Linux raid auto
1b Hidden W95 FAT3 70 DiskSecure Mult bb Boot Wizard hid fe LANstep
1c Hidden W95 FAT3 75 PC/IX be Solaris boot ff BBT
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): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
2）将分区修改同步至内存中
[[email protected] ~]# partprobe /dev/sdb
[[email protected] ~]# cat /proc/partitions
major minor #blocks name
8 0 20971520 sda
8 1 104391 sda1
8 2 20860402 sda2
8 16 20971520 sdb
8 17 56196 sdb1
8 18 24097 sdb2
8 19 104422 sdb3
8 20 0 sdb4
8 21 987966 sdb5
8 22 987966 sdb6
253 0 16744448 dm-0
253 1 4096000 dm-1
3）创建RAID 0
[[email protected] ~]# mdadm -C /dev/md0 -a yes -l 0 -n 2 /dev/sdb{5,6}
mdadm: array /dev/md0 started.
[[email protected] ~]# cat /proc/mdstat
Personalities : [raid0]
md0 : active raid0 sdb6[1] sdb5[0]
1975680 blocks 64k chunks
unused devices: <none>
[[email protected] ~]# mke2fs -j /dev/md0
mke2fs 1.39 (29-May-2006)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
247296 inodes, 493920 blocks
24696 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=507510784
16 block groups
32768 blocks per group, 32768 fragments per group
15456 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912
Writing inode tables: done
Creating journal (8192 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 39 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
创建一个2G的RAID 1:
1）创建3个分区/dev/sdb7 /dev/sdb8 /dev/sdb9
[[email protected] ~]# fdisk -l
Disk /dev/sda: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 13 104391 83 Linux
/dev/sda2 14 2610 20860402+ 8e Linux LVM
Disk /dev/sdb: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 7 56196 83 Linux
/dev/sdb2 8 10 24097+ 83 Linux
/dev/sdb3 11 23 104422+ 83 Linux
/dev/sdb4 24 2610 20780077+ 5 Extended
/dev/sdb5 24 146 987966 fd Linux raid autodetect
/dev/sdb6 147 269 987966 fd Linux raid autodetect
Disk /dev/md0: 2023 MB, 2023096320 bytes
2 heads, 4 sectors/track, 493920 cylinders
Units = cylinders of 8 * 512 = 4096 bytes
Disk /dev/md0 doesn't contain a valid partition table
[[email protected] ~]# mount /dev/md0 /mnt
[[email protected] ~]# ls /mnt/
lost+found
[[email protected] ~]# fdisk /dev/sdb
The number of cylinders for this disk is set to 2610.
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): n
First cylinder (270-2610, default 270):
Using default value 270
Last cylinder or +size or +sizeM or +sizeK (270-2610, default 2610): +2G
Command (m for help): n
First cylinder (514-2610, default 514):
Using default value 514
Last cylinder or +size or +sizeM or +sizeK (514-2610, default 2610): +2G
Command (m for help): n
First cylinder (758-2610, default 758):
Using default value 758
Last cylinder or +size or +sizeM or +sizeK (758-2610, default 2610): +2G
Command (m for help): t
Partition number (1-9): 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 (1-9): 8
Hex code (type L to list codes): fd
Changed system type of partition 8 to fd (Linux raid autodetect)
Command (m for help): t
Partition number (1-9): 9
Hex code (type L to list codes): fd
Changed system type of partition 9 to 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.
Syncing disks.
[[email protected] ~]# partprobe
Warning: Unable to open /dev/hdc read-write (Read-only file system). /dev/hdc has been opened read-only.
[[email protected] ~]# cat /proc/partitions
major minor #blocks name
8 0 20971520 sda
8 1 104391 sda1
8 2 20860402 sda2
8 16 20971520 sdb
8 17 56196 sdb1
8 18 24097 sdb2
8 19 104422 sdb3
8 20 0 sdb4
8 21 987966 sdb5
8 22 987966 sdb6
8 23 1959898 sdb7
8 24 1959898 sdb8
8 25 1959898 sdb9
253 0 16744448 dm-0
253 1 4096000 dm-1
9 0 1975680 md0
2）创建RAID1
[[email protected] ~]# mdadm -C /dev/md1 -a yes -n 2 -l 1 /dev/sdb7 /dev/sdb8
mdadm: array /dev/md1 started.
[[email protected] ~]# cat /proc/mdstat
Personalities : [raid0] [raid1]
md1 : active raid1 sdb8[1] sdb7[0]
1959808 blocks [2/2] [UU]
[===========>.........] resync = 58.3% (1144448/1959808) finish=0.0min speed=228889K/sec
md0 : active raid0 sdb6[1] sdb5[0]
1975680 blocks 64k chunks
unused devices: <none>
[[email protected] ~]# cat /proc/mdstat
Personalities : [raid0] [raid1]
md1 : active raid1 sdb8[1] sdb7[0]
1959808 blocks [2/2] [UU]
[===============>.....] resync = 77.8% (1527360/1959808) finish=0.0min speed=218194K/sec
md0 : active raid0 sdb6[1] sdb5[0]
1975680 blocks 64k chunks
unused devices: <none>
[[email protected] ~]# cat /proc/mdstat
Personalities : [raid0] [raid1]
md1 : active raid1 sdb8[1] sdb7[0]
1959808 blocks [2/2] [UU]
md0 : active raid0 sdb6[1] sdb5[0]
1975680 blocks 64k chunks
unused devices: <none>
[[email protected] ~]# fdisk -l
Disk /dev/sda: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 13 104391 83 Linux
/dev/sda2 14 2610 20860402+ 8e Linux LVM
Disk /dev/sdb: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 7 56196 83 Linux
/dev/sdb2 8 10 24097+ 83 Linux
/dev/sdb3 11 23 104422+ 83 Linux
/dev/sdb4 24 2610 20780077+ 5 Extended
/dev/sdb5 24 146 987966 fd Linux raid autodetect
/dev/sdb6 147 269 987966 fd Linux raid autodetect
/dev/sdb7 270 513 1959898+ fd Linux raid autodetect
/dev/sdb8 514 757 1959898+ fd Linux raid autodetect
/dev/sdb9 758 1001 1959898+ fd Linux raid autodetect
Disk /dev/md0: 2023 MB, 2023096320 bytes
2 heads, 4 sectors/track, 493920 cylinders
Units = cylinders of 8 * 512 = 4096 bytes
Disk /dev/md0 doesn't contain a valid partition table
Disk /dev/md1: 2006 MB, 2006843392 bytes
2 heads, 4 sectors/track, 489952 cylinders
Units = cylinders of 8 * 512 = 4096 bytes
Disk /dev/md1 doesn't contain a valid partition table
[[email protected]lhost ~]# mke2fs -j /dev/md1
mke2fs 1.39 (29-May-2006)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
245280 inodes, 489952 blocks
24497 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=503316480
15 block groups
32768 blocks per group, 32768 fragments per group
16352 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912
Writing inode tables: done
Creating journal (8192 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 32 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[[email protected] ~]# mount /dev/md1 /media/
[[email protected] ~]# cd /media/
[[email protected] media]# ls
lost+found
[[email protected] media]# cp /etc/inittab /media/
[[email protected] media]# ls
inittab lost+found
3）查看RAID阵列信息
[[email protected] media]# mdadm -D /dev/md1
/dev/md1:
Version : 0.90
Creation Time : Tue Jun 9 09:32:13 2020
Raid Level : raid1
Array Size : 1959808 (1914.20 MiB 2006.84 MB)
Used Dev Size : 1959808 (1914.20 MiB 2006.84 MB)
Raid Devices : 2
Total Devices : 2
Preferred Minor : 1
Persistence : Superblock is persistent
Update Time : Tue Jun 9 09:38:16 2020
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
UUID : 7ae4459f:59be4cf1:ced8169d:92d41837
Events : 0.4
Number Major Minor RaidDevice State
0 8 23 0 active sync /dev/sdb7
1 8 24 1 active sync /dev/sdb8
[[email protected] media]# mdadm --detail /dev/md1
/dev/md1:
Version : 0.90
Creation Time : Tue Jun 9 09:32:13 2020
Raid Level : raid1
Array Size : 1959808 (1914.20 MiB 2006.84 MB)
Used Dev Size : 1959808 (1914.20 MiB 2006.84 MB)
Raid Devices : 2
Total Devices : 2
Preferred Minor : 1
Persistence : Superblock is persistent
Update Time : Tue Jun 9 09:38:16 2020
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
UUID : 7ae4459f:59be4cf1:ced8169d:92d41837
Events : 0.4
Number Major Minor RaidDevice State
0 8 23 0 active sync /dev/sdb7
1 8 24 1 active sync /dev/sdb8
[[email protected] media]#
4）模拟损坏一个磁盘
[[email protected] ~]# mdadm /dev/md1 -f /dev/sdb8
mdadm: set /dev/sdb8 faulty in /dev/md1
[[email protected] ~]# mdadm -D /dev/md1
/dev/md1:
Version : 0.90
Creation Time : Tue Jun 9 09:32:13 2020
Raid Level : raid1
Array Size : 1959808 (1914.20 MiB 2006.84 MB)
Used Dev Size : 1959808 (1914.20 MiB 2006.84 MB)
Raid Devices : 2
Total Devices : 2
Preferred Minor : 1
Persistence : Superblock is persistent
Update Time : Tue Jun 9 09:40:53 2020
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 1
Spare Devices : 0
UUID : 7ae4459f:59be4cf1:ced8169d:92d41837
Events : 0.6
Number Major Minor RaidDevice State
0 8 23 0 active sync /dev/sdb7
1 0 0 1 removed
2 8 24 - faulty spare /dev/sdb8
[[email protected] ~]# cd /media/
[[email protected] media]# cat inittab
#
# inittab This file describes how the INIT process should set up
# the system in a certain run-level.
#
# Author: Miquel van Smoorenburg, <[email protected]>
# Modified for RHS Linux by Marc Ewing and Donnie Barnes
#
# Default runlevel. The runlevels used by RHS are:
# 0 - halt (Do NOT set initdefault to this)
# 1 - Single user mode
# 2 - Multiuser, without NFS (The same as 3, if you do not have networking)
# 3 - Full multiuser mode
# 4 - unused
# 5 - X11
# 6 - reboot (Do NOT set initdefault to this)
#
id:5:initdefault:
# System initialization.
si::sysinit:/etc/rc.d/rc.sysinit
l0:0:wait:/etc/rc.d/rc 0
l1:1:wait:/etc/rc.d/rc 1
l2:2:wait:/etc/rc.d/rc 2
l3:3:wait:/etc/rc.d/rc 3
l4:4:wait:/etc/rc.d/rc 4
l5:5:wait:/etc/rc.d/rc 5
l6:6:wait:/etc/rc.d/rc 6
# Trap CTRL-ALT-DELETE
ca::ctrlaltdel:/sbin/shutdown -t3 -r now
# When our UPS tells us power has failed, assume we have a few minutes
# of power left. Schedule a shutdown for 2 minutes from now.
# This does, of course, assume you have powerd installed and your
# UPS connected and working correctly.
pf::powerfail:/sbin/shutdown -f -h +2 "Power Failure; System Shutting Down"
# If power was restored before the shutdown kicked in, cancel it.
pr:12345:powerokwait:/sbin/shutdown -c "Power Restored; Shutdown Cancelled"
# Run gettys in standard runlevels
1:2345:respawn:/sbin/mingetty tty1
2:2345:respawn:/sbin/mingetty tty2
3:2345:respawn:/sbin/mingetty tty3
4:2345:respawn:/sbin/mingetty tty4
5:2345:respawn:/sbin/mingetty tty5
6:2345:respawn:/sbin/mingetty tty6
# Run xdm in runlevel 5
x:5:respawn:/etc/X11/prefdm -nodaemon
5）移除磁盘
[[email protected] media]# mdadm /dev/md1 -r /dev/sdb8
mdadm: hot removed /dev/sdb8
[[email protected] media]# mdadm –detail /dev/md1
/dev/md1:
Version : 0.90
Creation Time : Tue Jun 9 09:32:13 2020
Raid Level : raid1
Array Size : 1959808 (1914.20 MiB 2006.84 MB)
Used Dev Size : 1959808 (1914.20 MiB 2006.84 MB)
Raid Devices : 2
Total Devices : 1
Preferred Minor : 1
Persistence : Superblock is persistent
Update Time : Tue Jun 9 09:42:10 2020
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
UUID : 7ae4459f:59be4cf1:ced8169d:92d41837
Events : 0.12
Number Major Minor RaidDevice State
0 8 23 0 active sync /dev/sdb7
1 0 0 1 removed
6）将磁盘添加进阵列
[[email protected] media]# mdadm /dev/md1 -a /dev/sdb9
mdadm: added /dev/sdb9
[[email protected] media]# cat /proc/mdstat
Personalities : [raid0] [raid1]
md1 : active raid1 sdb9[1] sdb7[0]
1959808 blocks [2/2] [UU]
md0 : active raid0 sdb6[1] sdb5[0]
1975680 blocks 64k chunks
unused devices: <none>
[[email protected] media]# mdadm /dev/md1 -f /dev/sdb7
mdadm: set /dev/sdb7 faulty in /dev/md1
[[email protected] media]# mdadm -D /dev/md1
/dev/md1:
Version : 0.90
Creation Time : Tue Jun 9 09:32:13 2020
Raid Level : raid1
Array Size : 1959808 (1914.20 MiB 2006.84 MB)
Used Dev Size : 1959808 (1914.20 MiB 2006.84 MB)
Raid Devices : 2
Total Devices : 2
Preferred Minor : 1
Persistence : Superblock is persistent
Update Time : Tue Jun 9 09:44:28 2020
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 1
Spare Devices : 0
UUID : 7ae4459f:59be4cf1:ced8169d:92d41837
Events : 0.20
Number Major Minor RaidDevice State
0 0 0 0 removed
1 8 25 1 active sync /dev/sdb9
2 8 23 - faulty spare /dev/sdb7
[[email protected] media]# cat inittab
#
# inittab This file describes how the INIT process should set up
# the system in a certain run-level.
#
# Author: Miquel van Smoorenburg, <[email protected]>
# Modified for RHS Linux by Marc Ewing and Donnie Barnes
#
# Default runlevel. The runlevels used by RHS are:
# 0 - halt (Do NOT set initdefault to this)
# 1 - Single user mode
# 2 - Multiuser, without NFS (The same as 3, if you do not have networking)
# 3 - Full multiuser mode
# 4 - unused
# 5 - X11
# 6 - reboot (Do NOT set initdefault to this)
#
id:5:initdefault:
# System initialization.
si::sysinit:/etc/rc.d/rc.sysinit
l0:0:wait:/etc/rc.d/rc 0
l1:1:wait:/etc/rc.d/rc 1
l2:2:wait:/etc/rc.d/rc 2
l3:3:wait:/etc/rc.d/rc 3
l4:4:wait:/etc/rc.d/rc 4
l5:5:wait:/etc/rc.d/rc 5
l6:6:wait:/etc/rc.d/rc 6
# Trap CTRL-ALT-DELETE
ca::ctrlaltdel:/sbin/shutdown -t3 -r now
# When our UPS tells us power has failed, assume we have a few minutes
# of power left. Schedule a shutdown for 2 minutes from now.
# This does, of course, assume you have powerd installed and your
# UPS connected and working correctly.
pf::powerfail:/sbin/shutdown -f -h +2 "Power Failure; System Shutting Down"
# If power was restored before the shutdown kicked in, cancel it.
pr:12345:powerokwait:/sbin/shutdown -c "Power Restored; Shutdown Cancelled"
# Run gettys in standard runlevels
1:2345:respawn:/sbin/mingetty tty1
2:2345:respawn:/sbin/mingetty tty2
3:2345:respawn:/sbin/mingetty tty3
4:2345:respawn:/sbin/mingetty tty4
5:2345:respawn:/sbin/mingetty tty5
6:2345:respawn:/sbin/mingetty tty6
# Run xdm in runlevel 5
x:5:respawn:/etc/X11/prefdm -nodaemon
[[email protected] ~]# umount /media/
[[email protected] ~]# cat /proc/mdstat
Personalities : [raid0] [raid1]
md1 : active raid1 sdb9[1] sdb7[2](F)
1959808 blocks [2/1] [_U]
md0 : active raid0 sdb6[1] sdb5[0]
1975680 blocks 64k chunks
unused devices: <none>
7）停止阵列
[[email protected] ~]# mdadm -S /dev/md1
mdadm: stopped /dev/md1
[[email protected] ~]# cat /proc/mdstat
Personalities : [raid0] [raid1]
md0 : active raid0 sdb6[1] sdb5[0]
1975680 blocks 64k chunks
unused devices: <none>
8）启用阵列
[[email protected] ~]# mdadm -A /dev/md1 /dev/sda7 /dev/sda9
mdadm: cannot open device /dev/sda7: No such file or directory
mdadm: /dev/sda7 has no superblock - assembly aborted
[[email protected] ~]# mdadm -A /dev/md1 /dev/sdb7 /dev/sdb9
mdadm: /dev/md1 has been started with 1 drive (out of 2).
[[email protected] ~]# mdadm -D /dev/md1
/dev/md1:
Version : 0.90
Creation Time : Tue Jun 9 09:32:13 2020
Raid Level : raid1
Array Size : 1959808 (1914.20 MiB 2006.84 MB)
Used Dev Size : 1959808 (1914.20 MiB 2006.84 MB)
Raid Devices : 2
Total Devices : 1
Preferred Minor : 1
Persistence : Superblock is persistent
Update Time : Tue Jun 9 09:45:30 2020
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
UUID : 7ae4459f:59be4cf1:ced8169d:92d41837
Events : 0.26
Number Major Minor RaidDevice State
0 0 0 0 removed
1 8 25 1 active sync /dev/sdb9
[[email protected] ~]#
9）增加空闲盘
[[email protected] ~]# mdadm /dev/md1 -a /dev/sdb8
mdadm: added /dev/sdb8
[[email protected] ~]# mdadm -D /dev/md1
/dev/md1:
Version : 0.90
Creation Time : Tue Jun 9 09:32:13 2020
Raid Level : raid1
Array Size : 1959808 (1914.20 MiB 2006.84 MB)
Used Dev Size : 1959808 (1914.20 MiB 2006.84 MB)
Raid Devices : 2
Total Devices : 2
Preferred Minor : 1
Persistence : Superblock is persistent
Update Time : Tue Jun 9 10:05:44 2020
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
UUID : 7ae4459f:59be4cf1:ced8169d:92d41837
Events : 0.34
Number Major Minor RaidDevice State
0 8 24 0 active sync /dev/sdb8
1 8 25 1 active sync /dev/sdb9
[[email protected] ~]# mdadm /dev/md1 -a /dev/sdb7
mdadm: added /dev/sdb7
[[email protected] ~]# mdadm -D /dev/md1
/dev/md1:
Version : 0.90
Creation Time : Tue Jun 9 09:32:13 2020
Raid Level : raid1
Array Size : 1959808 (1914.20 MiB 2006.84 MB)
Used Dev Size : 1959808 (1914.20 MiB 2006.84 MB)
Raid Devices : 2
Total Devices : 3
Preferred Minor : 1
Persistence : Superblock is persistent
Update Time : Tue Jun 9 10:06:03 2020
State : clean
Active Devices : 2
Working Devices : 3
Failed Devices : 0
Spare Devices : 1
UUID : 7ae4459f:59be4cf1:ced8169d:92d41837
Events : 0.38
Number Major Minor RaidDevice State
0 8 24 0 active sync /dev/sdb8
1 8 25 1 active sync /dev/sdb9
2 8 23 - spare /dev/sdb7
[[email protected] ~]# mdadm /dev/md1 -f /dev/sdb9
mdadm: set /dev/sdb9 faulty in /dev/md1
[[email protected] ~]# mdadm -D /dev/md1
/dev/md1:
Version : 0.90
Creation Time : Tue Jun 9 09:32:13 2020
Raid Level : raid1
Array Size : 1959808 (1914.20 MiB 2006.84 MB)
Used Dev Size : 1959808 (1914.20 MiB 2006.84 MB)
Raid Devices : 2
Total Devices : 3
Preferred Minor : 1
Persistence : Superblock is persistent
Update Time : Tue Jun 9 10:09:32 2020
State : clean, degraded, recovering
Active Devices : 1
Working Devices : 2
Failed Devices : 1
Spare Devices : 1
Rebuild Status : 10% complete
UUID : 7ae4459f:59be4cf1:ced8169d:92d41837
Events : 0.40
Number Major Minor RaidDevice State
0 8 24 0 active sync /dev/sdb8
2 8 23 1 spare rebuilding /dev/sdb7
3 8 25 - faulty spare /dev/sdb9
[[email protected] ~]# watch "cat /proc/mdstat"
Every 2.0s: cat /proc/mdstat Tue Jun 9 10:09:43 2020
Personalities : [raid0] [raid1]
md1 : active raid1 sdb7[1] sdb8[0] sdb9[2](F)
1959808 blocks [2/2] [UU]
md0 : active raid0 sdb6[1] sdb5[0]
1975680 blocks 64k chunks
unused devices: <none>
[[email protected] ~]# mdadm -D /dev/md1
/dev/md1:
Version : 0.90
Creation Time : Tue Jun 9 09:32:13 2020
Raid Level : raid1
Array Size : 1959808 (1914.20 MiB 2006.84 MB)
Used Dev Size : 1959808 (1914.20 MiB 2006.84 MB)
Raid Devices : 2
Total Devices : 3
Preferred Minor : 1
Persistence : Superblock is persistent
Update Time : Tue Jun 9 10:09:42 2020
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 1
Spare Devices : 0
UUID : 7ae4459f:59be4cf1:ced8169d:92d41837
Events : 0.44
Number Major Minor RaidDevice State
0 8 24 0 active sync /dev/sdb8
1 8 23 1 active sync /dev/sdb7
2 8 25 - faulty spare /dev/sdb9
10）装配文件
[[email protected] ~]# mdadm -D --scan
ARRAY /dev/md0 level=raid0 num-devices=2 metadata=0.90 UUID=e1e1cab6:474b148b:96446f97:91dacc41
ARRAY /dev/md1 level=raid1 num-devices=2 metadata=0.90 UUID=7ae4459f:59be4cf1:ced8169d:92d41837
[[email protected] ~]# mdadm -D --scan > /etc/mdadm.conf
[[email protected] ~]# mdadm -S /dev/md1
mdadm: stopped /dev/md1
[[email protected] ~]# mdadm -A /dev/md1
mdadm: /dev/md1 has been started with 2 drives.
[[email protected] ~]#
LVM
DM
Device Mapper
使用DM的功能：
LVM
快照
多路径
快照
所谓快照即保存存储空间创建快照那一刻的状态至快照中。以后从快照访问这个空间的数据始终为快照那一刻存储空间的状态。其原理为创建快照后，如果修改文件或删除文件将会复制一份这个文件至快照空间中，那么对于以后从快照空间访问这个存储空间的状态就有一下两种状态了：对于有改变的文件，访问的为快照中该文件改变前的备份；对于没有改变的文件，则为存储空间中的文件。
LVM介绍
来源
LVM（Logical Volume Manager），其作用是灵活的管理底层的物理存储空间。传统的磁盘管理方式中，在为系统分区时，很难精准评估和分配分区实际所需的容量。也许创建分区时所分配容量对于当前系统是满足需求的，但随着业务的增长，分区的容量很有可能将不再满足需求。传统的分区方式很难在不损坏分区的前提下对分区进行扩容。而LVM就可以动态的对分区进行扩容或者减少容量。
工作机制
在统的磁盘管理方式中，底层原始的磁盘由内核直接控制。而LVM通过将底层物理存储介质抽象的封装起来，然后以逻辑卷的方式呈现给上层应用。LVM管理的存储介质可以是硬盘分区、整个硬盘、raid阵列或者SAN硬盘。故LVM可以将不同种类的存储介质整合为一个更大的存储空间，以供操作系统使用，更易于磁盘空间的管理。
逻辑结构
术语：
l 物理存储介质（Physical Media）：LVM存储介质可以是硬盘分区、整个硬盘、raid阵列或者SAN硬盘，设备使用前必须初始化为LVM物理卷（PV）。
l 物理卷PV（Physical Volume）：物理存储介质被LVM初始化后就是一个个独立的PV。
l 物理盘区PE（Physical Extend）：PV中可分配的最小存储单元（参考分区的块和RAID的chunk），默认为4MB。
l 卷组VG（Volume Group）：一个或多个PV组成的存储空间集合。
l 逻辑卷LV（Logical Volume）：LV建立在VG上，一个VG可以建立多个LV，而一个LV最大可以独占整个VG。LV可以创建文件系统。若要对LV创建快照卷，那么快照卷必须跟LV在同一卷组。
l 逻辑盘区LE（Logical Extend）：LV中可分配的最小存储单元，其实就是PE，当它被分配给LV后被称为LE。
相关命令
|
功能/命令 |
物理卷管理 |
卷组管理 |
逻辑卷管理 |
|
扫描 |
pvscan |
vgscan |
lvscan |
|
建立 |
pvcreate |
vgcreate |
lvcreate |
|
显示 |
pvdisplay |
vgdisplay |
lvdisplay |
|
删除 |
pvremove |
vgremove |
lvremove |
|
扩展 |
vgextend |
lvextend |
|
|
缩小 |
vgreduce |
lvreduce |
示范
pv相关命令
1、创建两个分区，一个7G，一个3G
[[email protected] ~]# fdisk /dev/sdb
The number of cylinders for this disk is set to 2610.
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): n
First cylinder (24-2610, default 24):
Using default value 24
Last cylinder or +size or +sizeM or +sizeK (24-2610, default 2610): +7G
Command (m for help): n
First cylinder (876-2610, default 876):
Using default value 876
Last cylinder or +size or +sizeM or +sizeK (876-2610, default 2610): +3G
Command (m for help): t
Partition number (1-6): 5
Hex code (type L to list codes): L
0 Empty 1e Hidden W95 FAT1 80 Old Minix bf Solaris
1 FAT12 24 NEC DOS 81 Minix / old Lin c1 DRDOS/sec (FAT-
2 XENIX root 39 Plan 9 82 Linux swap / So c4 DRDOS/sec (FAT-
3 XENIX usr 3c PartitionMagic 83 Linux c6 DRDOS/sec (FAT-
4 FAT16 <32M 40 Venix 80286 84 OS/2 hidden C: c7 Syrinx
5 Extended 41 PPC PReP Boot 85 Linux extended da Non-FS data
6 FAT16 42 SFS 86 NTFS volume set db CP/M / CTOS / .
7 HPFS/NTFS 4d QNX4.x 87 NTFS volume set de Dell Utility
8 AIX 4e QNX4.x 2nd part 88 Linux plaintext df BootIt
9 AIX bootable 4f QNX4.x 3rd part 8e Linux LVM e1 DOS access
a OS/2 Boot Manag 50 OnTrack DM 93 Amoeba e3 DOS R/O
b W95 FAT32 51 OnTrack DM6 Aux 94 Amoeba BBT e4 SpeedStor
c W95 FAT32 (LBA) 52 CP/M 9f BSD/OS eb BeOS fs
e W95 FAT16 (LBA) 53 OnTrack DM6 Aux a0 IBM Thinkpad hi ee EFI GPT
f W95 Ext'd (LBA) 54 OnTrackDM6 a5 FreeBSD ef EFI (FAT-12/16/
10 OPUS 55 EZ-Drive a6 OpenBSD f0 Linux/PA-RISC b
11 Hidden FAT12 56 Golden Bow a7 NeXTSTEP f1 SpeedStor
12 Compaq diagnost 5c Priam Edisk a8 Darwin UFS f4 SpeedStor
14 Hidden FAT16 <3 61 SpeedStor a9 NetBSD f2 DOS secondary
16 Hidden FAT16 63 GNU HURD or Sys ab Darwin boot fb VMware VMFS
17 Hidden HPFS/NTF 64 Novell Netware b7 BSDI fs fc VMware VMKCORE
18 AST SmartSleep 65 Novell Netware b8 BSDI swap fd Linux raid auto
1b Hidden W95 FAT3 70 DiskSecure Mult bb Boot Wizard hid fe LANstep
1c Hidden W95 FAT3 75 PC/IX be Solaris boot ff BBT
Hex code (type L to list codes): 8e
Changed system type of partition 5 to 8e (Linux LVM)
Command (m for help): t
Partition number (1-6): 6
Hex code (type L to list codes): 8e
Changed system type of partition 6 to 8e (Linux LVM)
Command (m for help): p
Disk /dev/sdb: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 7 56196 83 Linux
/dev/sdb2 8 10 24097+ 83 Linux
/dev/sdb3 11 23 104422+ 83 Linux
/dev/sdb4 24 2610 20780077+ 5 Extended
/dev/sdb5 24 875 6843658+ 8e Linux LVM
/dev/sdb6 876 1241 2939863+ 8e Linux LVM
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
[[email protected] ~]# partprobe
Warning: Unable to open /dev/hdc read-write (Read-only file system). /dev/hdc has been opened read-only.
You have new mail in /var/spool/mail/root
[[email protected] ~]# cat /proc/partitions
major minor #blocks name
8 0 20971520 sda
8 1 104391 sda1
8 2 20860402 sda2
8 16 20971520 sdb
8 17 56196 sdb1
8 18 24097 sdb2
8 19 104422 sdb3
8 20 0 sdb4
8 21 6843658 sdb5
8 22 2939863 sdb6
253 0 16744448 dm-0
253 1 4096000 dm-1
2、将两个分区初始化为PV
[[email protected] ~]# pvcreate /dev/sdb{5,6}
Writing physical volume data to disk "/dev/sdb5"
Physical volume "/dev/sdb5" successfully created
Writing physical volume data to disk "/dev/sdb6"
Physical volume "/dev/sdb6" successfully created
3、查看pv信息，此时PV还不属于VG
[[email protected] ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 VolGroup00 lvm2 a-- 19.88G 0
/dev/sdb5 lvm2 a-- 6.53G 6.53G
/dev/sdb6 lvm2 a-- 2.80G 2.80G
4、查看PV详细信息
[[email protected] ~]# pvdisplay
--- Physical volume ---
PV Name /dev/sda2
VG Name VolGroup00
PV Size 19.89 GB / not usable 19.49 MB
Allocatable yes (but full)
PE Size (KByte) 32768
Total PE 636
Free PE 0
Allocated PE 636
PV UUID 2BG10i-1wjr-Cw2h-113k-WHkQ-2Sa8-3X4sVu
"/dev/sdb5" is a new physical volume of "6.53 GB"
--- NEW Physical volume ---
PV Name /dev/sdb5
VG Name
PV Size 6.53 GB
Allocatable NO
PE Size (KByte) 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID Cgu1bO-ImVC-oJtD-62Ky-GFwT-RU24-FLgkp9
"/dev/sdb6" is a new physical volume of "2.80 GB"
--- NEW Physical volume ---
PV Name /dev/sdb6
VG Name
PV Size 2.80 GB
Allocatable NO
PE Size (KByte) 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID QbFf65-K1x2-tNJI-nQdX-aVlE-CPvi-d4R45p
5、扫描PV
[[email protected] ~]# pvscan
PV /dev/sda2 VG VolGroup00 lvm2 [19.88 GB / 0 free]
PV /dev/sdb5 lvm2 [6.53 GB]
PV /dev/sdb6 lvm2 [2.80 GB]
Total: 3 [29.21 GB] / in use: 1 [19.88 GB] / in no VG: 2 [9.33 GB]
VG相关
1、创建VG
[[email protected] ~]# vgcreate myvg /dev/sdb{5,6}
Volume group "myvg" successfully created
2、查看VG信息
[[email protected] ~]# vgs
VG #PV #LV #SN Attr VSize VFree
VolGroup00 1 2 0 wz--n- 19.88G 0
myvg 2 0 0 wz--n- 9.32G 9.32G
[[email protected] ~]# vgdisplay myvg
--- Volume group ---
VG Name myvg
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 1
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 0
Open LV 0
Max PV 0
Cur PV 2
Act PV 2
VG Size 9.32 GB
PE Size 4.00 MB
Total PE 2387
Alloc PE / Size 0 / 0
Free PE / Size 2387 / 9.32 GB
VG UUID sojtAt-Tgn0-2DnW-MpJ5-deDN-pS9U-9lw9GX
[[email protected] ~]# pvdisplay /dev/sdb5
--- Physical volume ---
PV Name /dev/sdb5
VG Name myvg
PV Size 6.53 GB / not usable 3.26 MB
Allocatable yes
PE Size (KByte) 4096
Total PE 1670
Free PE 1670
Allocated PE 0
PV UUID Cgu1bO-ImVC-oJtD-62Ky-GFwT-RU24-FLgkp9
3、移除VG
[[email protected] ~]# vgremove myvg
Volume group "myvg" successfully removed
[[email protected] ~]# vgs
VG #PV #LV #SN Attr VSize VFree
VolGroup00 1 2 0 wz--n- 19.88G 0
4、创建一个PE为8M的VG
[[email protected] ~]# vgcreate -s 8M myvg /dev/sdb{5,6}
Volume group "myvg" successfully created
[[email protected] ~]# vgdisplay myvg
--- Volume group ---
VG Name myvg
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 1
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 0
Open LV 0
Max PV 0
Cur PV 2
Act PV 2
VG Size 9.32 GB
PE Size 8.00 MB
Total PE 1193
Alloc PE / Size 0 / 0
Free PE / Size 1193 / 9.32 GB
VG UUID pamHGj-tjjl-OMQd-o9Hd-xTo7-02Dy-TEYAm8
[[email protected] ~]# vgs
VG #PV #LV #SN Attr VSize VFree
VolGroup00 1 2 0 wz--n- 19.88G 0
myvg 2 0 0 wz--n- 9.32G 9.32G
[[email protected] ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 VolGroup00 lvm2 a-- 19.88G 0
/dev/sdb5 myvg lvm2 a-- 6.52G 6.52G
/dev/sdb6 myvg lvm2 a-- 2.80G 2.80G
5、删除vg中的pv
1）首先转移pv中数据
[[email protected] ~]# pvmove /dev/sdb6
No data to move for myvg
2）再删除PV
[[email protected] ~]# vgreduce myvg /dev/sdb6
Removed "/dev/sdb6" from volume group "myvg"
[[email protected] ~]# vgs
VG #PV #LV #SN Attr VSize VFree
VolGroup00 1 2 0 wz--n- 19.88G 0
myvg 1 0 0 wz--n- 6.52G 6.52G
[[email protected] ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 VolGroup00 lvm2 a-- 19.88G 0
/dev/sdb5 myvg lvm2 a-- 6.52G 6.52G
/dev/sdb6 lvm2 a-- 2.80G 2.80G
3）当PV没有被使用时可以删除
[[email protected] ~]# pvremove /dev/sdb6
Labels on physical volume "/dev/sdb6" successfully wiped
[[email protected] ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 VolGroup00 lvm2 a-- 19.88G 0
/dev/sdb5 myvg lvm2 a-- 6.52G 6.52G
6、扩展VG
1）创建一个5G的分区
[[email protected] ~]# fdisk /dev/sdb
The number of cylinders for this disk is set to 2610.
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): n
First cylinder (1242-2610, default 1242):
Using default value 1242
Last cylinder or +size or +sizeM or +sizeK (1242-2610, default 2610): +5G
Command (m for help): t
Partition number (1-7): 7
Hex code (type L to list codes): 8e
Changed system type of partition 7 to 8e (Linux LVM)
Command (m for help): p
Disk /dev/sdb: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 7 56196 83 Linux
/dev/sdb2 8 10 24097+ 83 Linux
/dev/sdb3 11 23 104422+ 83 Linux
/dev/sdb4 24 2610 20780077+ 5 Extended
/dev/sdb5 24 875 6843658+ 8e Linux LVM
/dev/sdb6 876 1241 2939863+ 8e Linux LVM
/dev/sdb7 1242 1850 4891761 8e Linux LVM
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.
Syncing disks.
[[email protected] ~]# partprobe
Warning: Unable to open /dev/hdc read-write (Read-only file system). /dev/hdc has been opened read-only.
[[email protected] ~]# cat /proc/partitions
major minor #blocks name
8 0 20971520 sda
8 1 104391 sda1
8 2 20860402 sda2
8 16 20971520 sdb
8 17 56196 sdb1
8 18 24097 sdb2
8 19 104422 sdb3
8 20 0 sdb4
8 21 6843658 sdb5
8 22 2939863 sdb6
8 23 4891761 sdb7
253 0 16744448 dm-0
253 1 4096000 dm-1
[[email protected] ~]# pvcreate /dev/sdb7
Writing physical volume data to disk "/dev/sdb7"
Physical volume "/dev/sdb7" successfully created
2）扩展一个新的PV到VG中
[[email protected] ~]# vgextend myvg /dev/sdb7
Volume group "myvg" successfully extended
[[email protected] ~]# vgs
VG #PV #LV #SN Attr VSize VFree
VolGroup00 1 2 0 wz--n- 19.88G 0
myvg 2 0 0 wz--n- 11.19G 11.19G
LV相关
1、创建LV
[[email protected] ~]# lvcreate -L 50M -n testlv myvg
Rounding up size to full physical extent 56.00 MB
Logical volume "testlv" created
[[email protected] ~]# lvs
LV VG Attr LSize Origin Snap% Move Log Copy% Convert
LogVol00 VolGroup00 -wi-ao 15.97G
LogVol01 VolGroup00 -wi-ao 3.91G
testlv myvg -wi-a- 56.00M
[[email protected] ~]# lvdisplay
--- Logical volume ---
LV Name /dev/myvg/testlv
VG Name myvg
LV UUID d9XeJm-r7mK-RcXm-S31l-YW4I-nI5l-80LDYK
LV Write Access read/write
LV Status available
# open 0
LV Size 56.00 MB
Current LE 7
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:2
--- Logical volume ---
LV Name /dev/VolGroup00/LogVol00
VG Name VolGroup00
LV UUID 3iBZqe-w3g6-PdI2-nfyv-QQJF-rzhg-KKR4H2
LV Write Access read/write
LV Status available
# open 1
LV Size 15.97 GB
Current LE 511
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
--- Logical volume ---
LV Name /dev/VolGroup00/LogVol01
VG Name VolGroup00
LV UUID FS3Hpm-zJcc-YFA7-gTSl-yI7M-zRsw-8t8NJQ
LV Write Access read/write
LV Status available
# open 1
LV Size 3.91 GB
Current LE 125
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:1
[[email protected] ~]# lvdisplay /dev/myvg/testlv
--- Logical volume ---
LV Name /dev/myvg/testlv
VG Name myvg
LV UUID d9XeJm-r7mK-RcXm-S31l-YW4I-nI5l-80LDYK
LV Write Access read/write
LV Status available
# open 0
LV Size 56.00 MB
Current LE 7
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:2
2、创建文件系统
[[email protected] ~]# mke2fs -j /dev/myvg/testlv
mke2fs 1.39 (29-May-2006)
Filesystem label=
OS type: Linux
Block size=1024 (log=0)
Fragment size=1024 (log=0)
14336 inodes, 57344 blocks
2867 blocks (5.00%) reserved for the super user
First data block=1
Maximum filesystem blocks=58720256
7 block groups
8192 blocks per group, 8192 fragments per group
2048 inodes per group
Superblock backups stored on blocks:
8193, 24577, 40961
Writing inode tables: done
Creating journal (4096 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 38 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[[email protected] ~]# mount /dev/myvg/testlv /mnt
[[email protected] ~]# ls /mnt/
lost+found
[[email protected] ~]# mount
/dev/mapper/VolGroup00-LogVol00 on / type ext3 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
/dev/sda1 on /boot type ext3 (rw)
tmpfs on /dev/shm type tmpfs (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)
/dev/mapper/myvg-testlv on /mnt type ext3 (rw)
[[email protected] ~]# ls -l /dev/mapper/
total 0
crw------- 1 root root 10, 60 Jun 10 07:19 control
brw-rw---- 1 root disk 253, 2 Jun 10 08:43 myvg-testlv
brw-rw---- 1 root disk 253, 0 Jun 10 07:19 VolGroup00-LogVol00
brw-rw---- 1 root disk 253, 1 Jun 10 07:19 VolGroup00-LogVol01
3、lv的设备文件名只是一个软连接
[[email protected] ~]# ll /dev/myvg
total 0
lrwxrwxrwx 1 root root 23 Jun 10 08:42 testlv -> /dev/mapper/myvg-testlv/
4、删除lv
[[email protected] ~]# lvremove /dev/myvg/testlv
Can't remove open logical volume "testlv"
1）先卸载分区
[[email protected] ~]# umount /mnt/
2）再删除lv
[[email protected] ~]# lvremove /dev/myvg/testlv
Do you really want to remove active logical volume testlv? [y/n]: y
Logical volume "testlv" successfully removed
[[email protected] ~]# lvs
LV VG Attr LSize Origin Snap% Move Log Copy% Convert
LogVol00 VolGroup00 -wi-ao 15.97G
LogVol01 VolGroup00 -wi-ao 3.91G
[[email protected] ~]# lvcreate -L 2G -n testlv myvg
Logical volume "testlv" created
[[email protected] ~]# mke2fs -j /dev/myvg/testlv
mke2fs 1.39 (29-May-2006)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
262144 inodes, 524288 blocks
26214 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=536870912
16 block groups
32768 blocks per group, 32768 fragments per group
16384 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912
Writing inode tables: done
Creating journal (16384 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 28 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[[email protected] ~]# mkdir /users
[[email protected] ~]# mount /dev/myvg/testlv /users
[[email protected] ~]# cd /users/
[[email protected] users]# ls
lost+found
[[email protected] users]# cp /etc/inittab .
[[email protected] users]# cat inittab
#
# inittab This file describes how the INIT process should set up
# the system in a certain run-level.
…
[[email protected] ~]# df -lh
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
16G 3.0G 12G 21% /
/dev/sda1 99M 13M 81M 14% /boot
tmpfs 1004M 0 1004M 0% /dev/shm
/dev/mapper/myvg-testlv
2.0G 68M 1.9G 4% /users
5、扩展分区大小
1）先扩展lv大小
[[email protected] ~]# lvextend -L 5G /dev/myvg/testlv
Extending logical volume testlv to 5.00 GB
Logical volume testlv successfully resized
[[email protected] ~]# df -lh
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
16G 3.0G 12G 21% /
/dev/sda1 99M 13M 81M 14% /boot
tmpfs 1004M 0 1004M 0% /dev/shm
/dev/mapper/myvg-testlv
2.0G 68M 1.9G 4% /users
[[email protected] ~]# lvs
LV VG Attr LSize Origin Snap% Move Log Copy% Convert
LogVol00 VolGroup00 -wi-ao 15.97G
LogVol01 VolGroup00 -wi-ao 3.91G
testlv myvg -wi-ao 5.00G
2）再扩展文件系统大小
[[email protected] ~]# resize2fs -p /dev/myvg/testlv
resize2fs 1.39 (29-May-2006)
Filesystem at /dev/myvg/testlv is mounted on /users; on-line resizing required
Performing an on-line resize of /dev/myvg/testlv to 1310720 (4k) blocks.
The filesystem on /dev/myvg/testlv is now 1310720 blocks long.
[[email protected] ~]# df -lh
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
16G 3.0G 12G 21% /
/dev/sda1 99M 13M 81M 14% /boot
tmpfs 1004M 0 1004M 0% /dev/shm
/dev/mapper/myvg-testlv
5.0G 69M 4.7G 2% /users
[[email protected] ~]# cd /users/
[[email protected] users]# cat inittab
#
# inittab This file describes how the INIT process should set up
# the system in a certain run-level.
…
[[email protected] ~]# df -lh
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
16G 3.0G 12G 21% /
/dev/sda1 99M 13M 81M 14% /boot
tmpfs 1004M 0 1004M 0% /dev/shm
/dev/mapper/myvg-testlv
5.0G 69M 4.7G 2% /users
6、缩减分区大小
1）卸载分区
[[email protected] ~]# umount /users
[[email protected] ~]# mount
/dev/mapper/VolGroup00-LogVol00 on / type ext3 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
/dev/sda1 on /boot type ext3 (rw)
tmpfs on /dev/shm type tmpfs (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)
2）检查分区状态
[[email protected] ~]# e2fsck -f /dev/myvg/testlv
e2fsck 1.39 (29-May-2006)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/myvg/testlv: 12/655360 files (8.3% non-contiguous), 38002/1310720 blocks
3）缩减分区大小，缩减后的分区要能满足当前文件系统文件的容量
[[email protected] ~]# resize2fs /dev/myvg/testlv 3G
resize2fs 1.39 (29-May-2006)
Resizing the filesystem on /dev/myvg/testlv to 786432 (4k) blocks.
The filesystem on /dev/myvg/testlv is now 786432 blocks long.
4）缩减lV大小
[[email protected] ~]# lvreduce -L 3G /dev/myvg/testlv
WARNING: Reducing active logical volume to 3.00 GB
THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce testlv? [y/n]: y
Reducing logical volume testlv to 3.00 GB
Logical volume testlv successfully resized
[[email protected] ~]# mount /dev/myvg/testlv /users
[[email protected] ~]# df -lh
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
16G 3.0G 12G 21% /
/dev/sda1 99M 13M 81M 14% /boot
tmpfs 1004M 0 1004M 0% /dev/shm
/dev/mapper/myvg-testlv
3.0G 68M 2.8G 3% /users
[[email protected] ~]# cd /users/
[[email protected] users]# cat inittab
#
# inittab This file describes how the INIT process should set up
# the system in a certain run-level.
…
创建快照卷
[[email protected] ~]# lvcreate -L 50M -n testlv-snap -s -p r /dev/myvg/testlv
Rounding up size to full physical extent 56.00 MB
Logical volume "testlv-snap" created
[[email protected] ~]# lvs
LV VG Attr LSize Origin Snap% Move Log Copy% Convert
LogVol00 VolGroup00 -wi-ao 15.97G
LogVol01 VolGroup00 -wi-ao 3.91G
testlv myvg owi-ao 3.00G
testlv-snap myvg sri-a- 56.00M testlv 0.02
[[email protected] ~]# mount /dev/myvg/testlv
testlv testlv-snap
[[email protected] ~]# mount /dev/myvg/testlv-snap /mnt
mount: block device /dev/myvg/testlv-snap is write-protected, mounting read-only
[[email protected] ~]# cd /mnt/
[[email protected] mnt]# ls
inittab lost+found