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Linux命令：pv,vg,lg,快照
PV: physical volume
pvcreate, pvdisplay, pvs, pvmove, pvremove
VG: volume group
vgcreate, vgdisplay, vgs, vgreduce, vgextend, vgremove
lV: logical volume
lvcreate, lvdisplay, lvs, lvreduce, lvextend, lvresize, lvremove
一、PV新增、删除、查看、扫描
[root@localhost ~]# pvscan
PV /dev/sda10 VG VolGroup00 lvm2 [1.41 GB / 1.41 GB free]
Total: 1 [1.41 GB] / in use: 1 [1.41 GB] / in no VG: 0 [0 ]
[root@localhost ~]# vgs
VG #PV #LV #SN Attr VSize VFree
VolGroup00 1 0 0 wz--n- 1.41G 1.41G
[root@localhost ~]# vgcreate myvg /dev/sdb{1,2} ***未建pv时，无法直接建vg，会出错
No physical volume label read from /dev/sdb1
/dev/sdb1 not identified as an existing physical volume
Unable to add physical volume ‘/dev/sdb1‘ to volume group ‘myvg‘.
[root@localhost ~]# vgs
VG #PV #LV #SN Attr VSize VFree
VolGroup00 1 0 0 wz--n- 1.41G 1.41G
[root@localhost ~]# pvcreate /dev/sdb{1,2}
Physical volume "/dev/sdb1" successfully created
Physical volume "/dev/sdb2" successfully created
[root@localhost ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda10 VolGroup00 lvm2 a- 1.41G 1.41G
/dev/sdb1 lvm2 -- 494.16M 494.16M
/dev/sdb2 lvm2 -- 980.53M 980.53M
[root@localhost ~]# pvdisplay
"/dev/sdb1" is a new physical volume of "494.16 MB"
--- NEW Physical volume ---
PV Name /dev/sdb1
VG Name
PV Size 494.16 MB
Allocatable NO
PE Size (KByte) 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID 0eFqhA-maz7-mgxp-YG7A-UU8N-yE7b-zUMKwa
"/dev/sdb2" is a new physical volume of "980.53 MB"
--- NEW Physical volume ---
PV Name /dev/sdb2
VG Name
PV Size 980.53 MB
Allocatable NO
PE Size (KByte) 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID WwfLj0-FxRD-JzrI-F9K5-T352-f3ho-4r2lVx
[root@localhost ~]# pvscan ***新硬盘中扫描后方可识别
PV /dev/sda10 VG VolGroup00 lvm2 [1.41 GB / 1.41 GB free]
PV /dev/sdb1 lvm2 [494.16 MB]
PV /dev/sdb2 lvm2 [980.53 MB]
Total: 3 [2.85 GB] / in use: 1 [1.41 GB] / in no VG: 2 [1.44 GB]
二、VG新增、删除、查看、扫描
[root@localhost ~]# vgcreate myvg /dev/sdb{1,2}
Volume group "myvg" successfully created
[root@localhost ~]# 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 1.44 GB
PE Size 4.00 MB
Total PE 368
Alloc PE / Size 0 / 0
Free PE / Size 368 / 1.44 GB
VG UUID iqm9Zu-qHSZ-Evnw-PNxq-FcbI-AShe-nhN5Oj
[root@localhost ~]# pvdisplay /dev/sdb1
--- Physical volume ---
PV Name /dev/sdb1
VG Name myvg
PV Size 494.16 MB / not usable 2.16 MB
Allocatable yes
PE Size (KByte) 4096
Total PE 123
Free PE 123
Allocated PE 0
PV UUID 0eFqhA-maz7-mgxp-YG7A-UU8N-yE7b-zUMKwa
[root@localhost ~]# vgremove myvg ***删除vg
Volume group "myvg" successfully removed
[root@localhost ~]# vgs
VG #PV #LV #SN Attr VSize VFree
VolGroup00 1 0 0 wz--n- 1.41G 1.41G ***VG 1.41G***
[root@localhost ~]# vgcreate -s 8M myvg /dev/sdb{1,2}
Volume group "myvg" successfully created
[root@localhost ~]# 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 1.43 GB
PE Size 8.00 MB
Total PE 183
Alloc PE / Size 0 / 0
Free PE / Size 183 / 1.43 GB
VG UUID TC2ZaN-P1IW-KFGe-CPU3-wZcx-eSJi-qbSi6C
[root@localhost ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sdb1 myvg lvm2 a- 488.00M 488.00M
/dev/sdb2 myvg lvm2 a- 976.00M 976.00M ***/dev/sdb2属于组myvg
[root@localhost ~]# pvmove /dev/sdb2
No data to move for myvg
[root@localhost ~]# vgreduce myvg /dev/sdb2
Removed "/dev/sdb2" from volume group "myvg"
[root@localhost ~]# vgs
VG #PV #LV #SN Attr VSize VFree
myvg 1 0 0 wz--n- 488.00M 488.00M ***VG 1.41G减少为488.00M***
[root@localhost ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sdb1 myvg lvm2 a- 488.00M 488.00M
/dev/sdb2 lvm2 -- 980.53M 980.53M ***/dev/sdb2不属于任何组
[root@localhost ~]# pvremove /dev/sdb2
Labels on physical volume "/dev/sdb2" successfully wiped ***删除PV
[root@localhost ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sdb1 myvg lvm2 a- 488.00M 488.00M
[root@localhost ~]# pvcreate /dev/sdb2 ***创建PV
Physical volume "/dev/sdb2" successfully created
[root@localhost ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sdb1 myvg lvm2 a- 488.00M 488.00M
/dev/sdb2 lvm2 -- 980.53M 980.53M
[root@localhost ~]# vgextend myvg /dev/sdb2 ***将PV加入，延伸VG
Volume group "myvg" successfully extended
[root@localhost ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sdb1 myvg lvm2 a- 488.00M 488.00M
/dev/sdb2 myvg lvm2 a- 976.00M 976.00M
[root@localhost ~]# vgs
VG #PV #LV #SN Attr VSize VFree
myvg 2 0 0 wz--n- 1.43G 1.43G
[root@localhost ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda10 VolGroup00 lvm2 a- 1.41G 1.41G
/dev/sdb1 myvg lvm2 a- 488.00M 488.00M
/dev/sdb2 myvg lvm2 a- 976.00M 976.00M
三、LV新增、删除、查看、扫描
[root@localhost ~]# lvcreate -L 50M -n testlv myvg
Rounding up size to full physical extent 56.00 MB
Logical volume "testlv" created
[root@localhost ~]# lvs
LV VG Attr LSize Origin Snap% Move Log Copy% Convert
testlv myvg -wi-a- 56.00M
[root@localhost ~]# lvdisplay
--- Logical volume ---
LV Name /dev/myvg/testlv
VG Name myvg
LV UUID zXwoKM-OYnU-EWAC-EBoD-dFTh-l4sE-ip1m3q
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 253:0
[root@localhost ~]# mke2fs -j /dev/myvg/testlv
[root@localhost ~]# mount /dev/myvg/testlv /mnt
[root@localhost ~]# ls /mnt/
lost+found
[root@localhost ~]# mount
/dev/mapper/myvg-testlv on /mnt type ext3 (rw) ***myvg-testlv名称中含有‘ - ’，故LV的名称不可使用-
[root@localhost ~]# lvremove /dev/mapper/myvg-testlv
Can‘t remove open logical volume "testlv" ***挂载中的LV不能正常删除
[root@localhost ~]# umount /mnt
[root@localhost ~]# lvremove /dev/mapper/myvg-testlv
Do you really want to remove active logical volume testlv? [y/n]: y
Logical volume "testlv" successfully removed
[root@localhost ~]# lvs
A、新建200M的LV，并将空间扩展到300M，可在线扩展
[root@localhost ~]# lvcreate -L 200M -n testlv myvg ***新建200M的LV
Logical volume "testlv" created
[root@localhost ~]# mke2fs -j /dev/myvg/testlv
[root@localhost ~]# vim /etc/fstab
/dev/myvg/testlv /users ext3 defaults,acl 0 0
[root@localhost ~]# mount -a
[root@localhost ~]# lvextend -L 300M /dev/myvg/testlv ***将LV扩展到300M
Rounding up size to full physical extent 304.00 MB
Extending logical volume testlv to 304.00 MB
Logical volume testlv successfully resized
[root@localhost ~]# lvs
LV VG Attr LSize Origin Snap% Move Log Copy% Convert
testlv myvg -wi-ao 304.00M
/dev/mapper/myvg-testlv 198337 5666 182431 4% /users
[root@localhost ~]# df -lh
Filesystem Size Used Avail Use% Mounted on
/dev/sda1 996M 40M 905M 5% /boot
tmpfs 3.9G 0 3.9G 0% /dev/shm
/dev/mapper/myvg-testlv
194M 5.6M 179M 4% /users ***LV扩展到300M后空间未变
[root@localhost ~]# lvs
LV VG Attr LSize Origin Snap% Move Log Copy% Convert
testlv myvg -wi-ao 304.00M
[root@localhost ~]# resize2fs -p /dev/myvg/testlv ***文件系统重定义大小
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 311296 (1k) blocks.
The filesystem on /dev/myvg/testlv is now 311296 blocks long.
[root@localhost ~]# df -lh
Filesystem Size Used Avail Use% Mounted on
/dev/sda1 996M 40M 905M 5% /boot
tmpfs 3.9G 0 3.9G 0% /dev/shm
/dev/mapper/myvg-testlv
295M 6.1M 274M 3% /users
[root@localhost ~]#
B、将空间为300M的LV，缩减到200M，必须卸载后方可缩减
1、不能在线缩减，得先卸载；
2、确保缩减后的空间大小依然能存储原有的所有数据；
3、在缩减之前应该先强行检查文件，以确保文件系统处于一至性状态；
[root@localhost ~]# mount 1***查看文件系统是否正在使用LV
[root@localhost /]# fuser -cu /users ***查看是否正在使用LV对应的挂载文件进程
/mnt: 15060c(root)
[root@localhost /]# fuser -ck /users ***清除正在使用LV对应挂载文件进程
/mnt: 15060c
[root@localhost ~]# umount /users/ 2***卸载文件
[root@localhost ~]# e2fsck -f /dev/myvg/testlv 3***检查文件，确保文件系统一致
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: 12/77824 files (8.3% non-contiguous), 15999/311296 blocks
[root@localhost ~]# df -lh 4***确保缩减后的空间大小依然能存储原有的所有数据
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/myvg-testlv 295M 5.6M 181M 3% /users
[root@localhost ~]# resize2fs /dev/myvg/testlv 200M 5***缩减到200M
resize2fs 1.39 (29-May-2006)
Resizing the filesystem on /dev/myvg/testlv to 204800 (1k) blocks.
The filesystem on /dev/myvg/testlv is now 204800 blocks long.
[root@localhost ~]# lvreduce -L 200M /dev/myvg/testlv
WARNING: Reducing active logical volume to 200.00 MB
THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce testlv? [y/n]: y
Reducing logical volume testlv to 200.00 MB
Logical volume testlv successfully resized
[root@localhost ~]# mount -a 6***重新挂载
[root@localhost ~]# df -lh
Filesystem Size Used Avail Use% Mounted on
/dev/sda1 996M 40M 905M 5% /boot
tmpfs 3.9G 0 3.9G 0% /dev/shm
/dev/mapper/myvg-testlv 194M 5.6M 181M 3% /users
C、创建快照卷，用于备份
1、生命周期为整个数据时长；在这段时长内，数据的增长量不能超出快照卷大小；
2、快照卷应该是只读的；
3、跟原卷在同一卷组内；
lvcreate
-s 创建快照
-p r|w LV权限，一般为r
-n 创建快照的逻辑卷名
lvcreate -L # -n SLV_NAME -p r /PATH/TO/LV
[root@localhost ~]# lvs
LV VG Attr LSize Origin Snap% Move Log Copy% Convert
testlv myvg -wi-ao 200.00M
[root@localhost ~]# lvcreate -L 20M -n TestSnap -s -p r /dev/myvg/testlv ***创建快照
Rounding up size to full physical extent 24.00 MB
Logical volume "TestSnap" created
[root@localhost ~]# lvs
LV VG Attr LSize Origin Snap% Move Log Copy% Convert
TestSnap myvg sri-a- 24.00M testlv 0.05
testlv myvg owi-ao 200.00M
[root@localhost ~]# mount /dev/myvg/TestSnap /mnt/
mount: block device /dev/myvg/TestSnap is write-protected, mounting read-only
[root@localhost ~]# ls /mnt/
inittab lost+found
[root@localhost ~]# cat /mnt/inittab | wc -l
53
[root@localhost ~]# mount
/dev/sda1 on /boot type ext3 (rw)
/dev/mapper/myvg-testlv on /users type ext3 (rw,acl)
/dev/mapper/myvg-TestSnap on /mnt type ext3 (ro)
[root@localhost ~]# cat /mnt/inittab | wc -l
53
[root@localhost ~]# vi /users/inittab ***创建快照后删除文件中8行文字，修改文件
[root@localhost ~]# cat /users/inittab | wc -l
41
[root@localhost ~]# cat /mnt/inittab | wc -l ***文件行数不变
53
[root@localhost ~]# cd /mnt/
[root@localhost mnt]# tar -jcf /tmp/users.tar.bz2 inittab ***将snap中文件压缩归档
[root@localhost mnt]# cd
[root@localhost ~]# umount /mnt/ ***将snap卸载
[root@localhost ~]# lvremove /dev/myvg/TestSnap ***将snap对应的LV删除
Do you really want to remove active logical volume TestSnap? [y/n]: y
Logical volume "TestSnap" successfully removed
[root@localhost users]# mv inittab inittab.bad ***将修改过的文件改名
[root@localhost users]# ll
total 14
-rw-r--r-- 1 root root 1356 Apr 25 11:04 inittab.bad
drwx------ 2 root root 12288 Apr 25 09:49 lost+found
[root@localhost users]# tar -xf /tmp/users.tar.bz2 -C ./ ***将归档的文件解压到原路径
[root@localhost users]# ll
total 16
-rw-r--r-- 1 root root 1666 Apr 25 09:52 inittab
-rw-r--r-- 1 root root 1356 Apr 25 11:04 inittab.bad
drwx------ 2 root root 12288 Apr 25 09:49 lost+found
[root@localhost users]# cat /users/inittab |wc -l ***归档的文件行数
53
[root@localhost users]# cat /users/inittab.bad |wc -l ***修改的文件数
41
---end---
Linux命令：pv,vg,lg,快照