创建LVM
- 划分分区,并指定适合的LVM的ID
[root@centos6 rf]# fdisk/dev/sdc使用fdisk划分一个分区；也可直接拿块新硬盘直接创建LVM逻辑卷
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0x3ca76d2c.
Changes will remain in memory only, until you decide to write them.
After that, of course, the previous content won't be recoverable.
Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)
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 查看/dev/sdc硬盘的分区情况；由于是新硬盘所以没有分区表
Disk /dev/sdc: 21.5 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 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: 0x3ca76d2c
Device Boot Start End Blocks Id System
Command (m for help): n 表示创建一个分区
Command action
e extended
p primary partition (1-4)
p 表示主分区 MBR分区表最多只允许4个主分区或3个主分区加一个扩展分区，可以扩展分区创建多个逻辑分区（e|p） e表示扩展分区；p表示主分区
Partition number (1-4): 1 分区号
First cylinder (1-2610, default 1): 指定开始的柱面这里如果不指定表示选择的是默认柱面，扩展分区不要让系统默认否则会出错
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-2610, default 2610): +10G 创建的大小可以指定柱面 也可以指定空间的大小
Command (m for help): t 调整分区的ID
Selected partition 1
Hex code (type L to list codes): l 查看系统默认支持的所有分区ID
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): 8e 这里选择8e 8e表示LVM
Changed system type of partition 1 to 8e (Linux LVM)
Command (m for help): p 查看分区情况
Disk /dev/sdc: 21.5 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 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: 0x3ca76d2c
Device Boot Start End Blocks Id System
/dev/sdc1 1 1306 10490413+ 8e Linux LVM
Command (m for help): w保存退出
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
- 注意 这里此磁盘分区已同步到内存中centos6新增磁盘同步分区表的
- partx -a /dev/DEVICE 或者 kpartx -a /dev/DEVICE -f: force
- centos6删除分区表同步的方法
- partx -d --nr M-N /dev/DEVICE
- CentOS 5 ，7: 增加分区或删除分区 使用partprobe
分区已划分创建LVM
- 创建物理卷
- [root@centos6 rf]# pvcreate /dev/sdc1
- Physical volume "/dev/sdc1" successfully created
- [root@centos6 rf]# pvdisplay 查看系统上所有的物理卷的详细信息
"/dev/sdc1" is a new physical volume of "10.00 GiB"
--- NEW Physical volume ---
PV Name /dev/sdc1
VG Name PV Size 10.00 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID n4NV1m-sr2p-A5K0-ckl4-681D-ah7g-HtYjmo
- [root@centos6 rf]# pvs 显示系统上物理卷的信息
PV VG Fmt Attr PSize PFree
/dev/sdc1 lvm2 ---- 10.00g 10.00g
- [root@centos6 rf]# vgcreate -s 10M vg0 /dev/sdc1 创建卷组 -s 指定PE大小 可以省略，省略表示选择默认值 后面跟的是卷组的名字 指定从哪个物理卷划分
- Volume group "vg0" successfully created
- [root@centos6 rf]# vgdisplay 查看卷组相关的信息
--- Volume group ---
VG Name vg0 卷组名称
System ID
Format lvm2
Metadata Areas 1
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 1
Act PV 1
VG Size 10.00 GiB 卷组总大小
PE Size 10.00 MiB PE大小
Total PE 1024 PE个数
Alloc PE / Size 0 / 0
Free PE / Size 1024 / 10.00 GiB
VG UUID ZujzGf-nNnJ-LfZb-ge6F-fiAP-MtHW-EepPhI
- [root@centos6 rf]# vgs 查看系统中的卷组
VG #PV #LV #SN Attr VSize VFree
vg0 1 0 0 wz--n- 10.00g 10.00g
[root@centos6 rf]# lvcreate -L 10G -n cx vg0 创建逻辑卷 -L 表示指定空间大小 -n 表示指定逻辑卷的名字 后面跟卷组名字表示从哪个卷组中划分逻辑分区
Logical volume "cx" created.
[root@centos6 rf]# mkfs.ext4 /dev/vg0/cx 创建文件系统
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
655360 inodes, 2621440 blocks
131072 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=2684354560
80 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 30 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
- [root@centos6 rf]# mkdir /cx 创建一个目录做挂载点
- [root@centos6 rf]# vim /etc/fstab 编辑 /etc/fstab添加“UUID=d7ab49ba-156c-4ca4-8e57-d2c6e8dd3076 /cx ext4 defaults 1 0
” - [root@centos6 ~]# blkid /dev/vg0/cx 查看UUID
/dev/vg0/cx: UUID="d7ab49ba-156c-4ca4-8e57-d2c6e8dd3076" TYPE="ext4"
- [root@centos6 rf]# mount -a 挂载/etc/fstab 文件中未挂载的设备
[root@centos6 rf]# mount 查看已挂载的设备
/dev/sda2 on / type ext4 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
tmpfs on /dev/shm type tmpfs (rw,rootcontext="system_u:object_r:tmpfs_t:s0")
/dev/sda1 on /boot type ext4 (rw)
/dev/sda6 on /home type ext4 (rw,usrquota)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
/dev/mapper/vg0-cx on /cx type ext4 (rw)
扩展LVM分区
- 1如果卷组里还有多余的空间，可以直接扩展逻辑卷；如果没有多余的空间就需要先扩展卷组
- 我这里先用一块新硬盘扩展物理卷再扩展卷组最后扩展逻辑分区
- [root@centos6 ~]# pvcreate /dev/sdd # 扩展物理卷 ；如果有多余的物理卷，可以直接扩展卷组
Physical volume "/dev/sdd" successfully created
[root@centos6 ~]# pvs 查看物理卷PV的信息
PV VG Fmt Attr PSize PFree
/dev/sdc1 vg0 lvm2 a--u 10.00g 0
/dev/sdd lvm2 ---- 60.00g 60.00g
[root@centos6 ~]# vgextend vg0 /dev/sdd 使用vgextend 扩展卷组（vg） 后面跟卷组名 指定把那个物理卷扩展到卷组
Volume group "vg0" successfully extended
- [root@centos6 ~]# vgdisplay
--- Volume group ---
VG Name vg0 卷组名字
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 3
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 1
Open LV 1
Max PV 0
Cur PV 2
Act PV 2
VG Size 69.99 GiB 卷组总大小
PE Size 10.00 MiB PE的大小
Total PE 7167 PE个数
Alloc PE / Size 1024 / 10.00 GiB 已分配的给逻辑卷（lv）使用的空间
Free PE / Size 6143 / 59.99 GiB 未分配空间
VG UUID ZujzGf-nNnJ-LfZb-ge6F-fiAP-MtHW-EepPhI
[root@centos6 ~]# lvextend -r -l +1000 /dev/vg0/cx 扩展逻辑卷并同步文件系统-r 表示同步文件系统
Size of logical volume vg0/cx changed from 10.00 GiB (1024 extents) to 19.77 GiB (2024 extents).
Logical volume cx successfully resized.
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/mapper/vg0-cx is mounted on /cx; on-line resizing required
old desc_blocks = 1, new_desc_blocks = 2
Performing an on-line resize of /dev/mapper/vg0-cx to 5181440 (4k) blocks.
The filesystem on /dev/mapper/vg0-cx is now 5181440 blocks long.
注意扩展逻辑卷无需取消挂载;建议提前备份数据
缩减逻辑卷
- 先取消挂载
- [root@centos6 ~]# umount /dev/vg0/cx
- 检查文件系统完整性，这一步必须否则系统不让缩
- [root@centos6 ~]# e2fsck -f /dev/vg0/cx
e2fsck 1.41.12 (17-May-2010)
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/vg0/cx: 11/1302528 files (0.0% non-contiguous), 121551/5181440 blocks
- 缩减文件系统到15G
[root@centos6 ~]# resize2fs /dev/vg0/cx 15G
resize2fs 1.41.12 (17-May-2010)
Resizing the filesystem on /dev/vg0/cx to 3932160 (4k) blocks.
The filesystem on /dev/vg0/cx is now 3932160 blocks long.
- 缩减逻辑卷到15G，注意这里缩减的大小与文件系统大小一致
- [root@centos6 ~]# lvreduce -L 15G /dev/vg0/cx
WARNING: Reducing active logical volume to 15.00 GiB.
THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce vg0/cx? [y/n]: y 提醒用户缩减空间可能会损坏数据
Size of logical volume vg0/cx changed from 19.77 GiB (2024 extents) to 15.00 GiB (1536 extents).
Logical volume cx successfully resized.
缩减逻辑卷成
创建逻辑卷快照
- [root@centos6 ~]# mount -a 挂载文件系统
- [root@centos6 ~]# mount
/dev/sda2 on / type ext4 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
tmpfs on /dev/shm type tmpfs (rw,rootcontext="system_u:object_r:tmpfs_t:s0")
/dev/sda1 on /boot type ext4 (rw)
/dev/sda6 on /home type ext4 (rw,usrquota)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
/dev/mapper/vg0-cx on /cx type ext4 (rw)
拷贝数据
- [root@centos6 ~]# cp /etc/passwd /cx/
- [root@centos6 ~]# ls /cx/
lost+found passwd
- 创建快照
- [root@centos6 ~]# lvcreate -L 1G -s -n cx-date -p r /dev/vg0/cx
Rounding up size to full physical extent 1.01 GiB
Logical volume "cx-date" created.
- [root@centos6 ~]# mkdir ll
- [root@centos6 ~]# mount /dev/vg0/cx-date ll
mount: block device /dev/mapper/vg0-cx--date is write-protected, mounting read-only 挂载快照
- [root@centos6 ~]# ls l 查看快照
lost+found passwd
- [root@centos6 ~]# rm -rf /cx/passwd 删除源文件的部分数据
取消逻辑卷与快照的挂载 - [root@centos6 ~]# umount /cx/
- [root@centos6 ~]# umount ll/
- 恢复快照 注意恢复快照会被删除
- [root@centos6 ~]# lvconvert --merge /dev/vg0/cx-date
Merging of volume cx-date started. cx: Merged: 100.0% Merge of snapshot into logical volume cx has finished. Logical volume "cx-date" successfully removed - 快照被删除
- [root@centos6 ~]# lvdisplay
--- Logical volume ---
LV Path /dev/vg0/cx
LV Name cx
VG Name vg0
LV UUID YqujVe-SSvL-BDFZ-TuPu-YMTg-lXTe-DnlubY
LV Write Access read/write
LV Creation host, time centos6.chenxi.com, 2017-06-24 08:52:01 +0800
LV Status available
# open 0
LV Size 15.00 GiB
Current LE 1536
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
查看是否成功恢复
- [root@centos6 ~]# mount -a
- [root@centos6 ~]# cat /cx/passwd
root:x:0:0:root:/root:/bin/bash
bin:x:1:1:bin:/bin:/sbin/nologin......
迁移LVM到其他主机，先取消挂载
- 迁移前改个名字 如果目标主机没有重复名字的卷组就不用更改
- vgrename 原名 新名字
- lvrename 原名 新名字 改逻辑卷的名字
- umount /cx/取消挂载
- pvmove /dev/sdc1 迁移PE空间，迁移前应先查看卷组PE空间是否够sdc1 PE空间使用，如果不够应先扩展卷组空间
- vgchange -an vg0 禁用卷组
- vgexport vg0 导出卷组
- 拔出对应的硬盘拔出
在目标计算机上 - 在新系统中安装旧硬盘，并vgimport vg0.
- vgchange –ay vg0 启用卷组
- mount 挂载
