linux的逻辑卷管理
一、逻辑卷介绍
逻辑卷
作用：1.整合分散的空间
2.空间支持扩大逻辑卷制作过程：将众多的物理卷（PV）组建成卷组（VG），再从卷组中划分出逻辑卷（LV）
二、建立卷组和逻辑卷
// 建立卷组（VG）
// 格式：vgcreate 卷组名 设备路径…….
[root@www ~]# vgcreate systemvg /dev/sdb[1-2]
// 该处是因为之前的sdb1做了交换空间，正常是直接会成功
WARNING: swap signature detected on /dev/sdb1 at offset 4086. Wipe it? [y/n]: y
Wiping swap signature on /dev/sdb1.
Physical volume "/dev/sdb1" successfully created.
Physical volume "/dev/sdb2" successfully created.
Volume group "systemvg" successfully created
// 查看物理卷的信息
[root@www ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 centos lvm2 a-- <59.00g 4.00m
/dev/sdb1 systemvg lvm2 a-- 1020.00m 1020.00m
/dev/sdb2 systemvg lvm2 a-- 1020.00m 1020.00m
// 查看卷组的信息
[root@www ~]# vgs
VG #PV #LV #SN Attr VSize VFree
centos 1 3 0 wz--n- <59.00g 4.00m
systemvg 2 0 0 wz--n- 1.99g 1.99g
// 可以看到此时的centos也是一个卷组
[root@www ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 60G 0 disk
├─sda1 8:1 0 1G 0 part /boot
└─sda2 8:2 0 59G 0 part
├─centos-root 253:0 0 38.3G 0 lvm /
├─centos-swap 253:1 0 2G 0 lvm [SWAP]
└─centos-home 253:2 0 18.7G 0 lvm /home
sdb 8:16 0 10G 0 disk
├─sdb1 8:17 0 1G 0 part
├─sdb2 8:18 0 1G 0 part
├─sdb3 8:19 0 1G 0 part
├─sdb4 8:20 0 1K 0 part
└─sdb5 8:21 0 1G 0 part
sdc 8:32 0 10G 0 disk
├─sdc1 8:33 0 953.7M 0 part
└─sdc2 8:34 0 3.7G 0 part
sr0 11:0 1 4.3G 0 rom /mydvd
// 建立逻辑卷（LV）
// 格式: lvcreate -L 大小G -n 逻辑卷名字 卷组名
[root@www ~]# lvcreate -L 1G -n vo systemvg
Logical volume "vo" created.
// 查看逻辑卷信息
[root@www ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
home centos -wi-ao---- <18.70g
root centos -wi-ao---- <38.30g
swap centos -wi-ao---- 2.00g
vo systemvg -wi-a----- 1.00g
[root@www ~]# ls /dev/systemvg/vo
/dev/systemvg/vo
// 此处是系统自动做了链接
[root@www ~]# ls -l /dev/systemvg/vo
lrwxrwxrwx. 1 root root 7 Dec 22 03:08 /dev/systemvg/vo -> ../dm-3
// 格式化刚才创建的逻辑卷
[root@www ~]# mkfs.xfs /dev/systemvg/vo
meta-data=/dev/systemvg/vo isize=512 agcount=4, agsize=65536 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0, sparse=0
data = bsize=4096 blocks=262144, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal log bsize=4096 blocks=2560, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
// 查看逻辑卷的类型为xfs
[root@www ~]# blkid /dev/systemvg/vo
/dev/systemvg/vo: UUID="35d7aecf-5e01-42c2-916f-f52ba8fc8d7c" TYPE="xfs"
[root@www ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 centos lvm2 a-- <59.00g 4.00m
/dev/sdb1 systemvg lvm2 a-- 1020.00m 0
/dev/sdb2 systemvg lvm2 a-- 1020.00m 1016.00m
// 此时可以看到们的systemvg增加了一个LV
[root@www ~]# vgs
VG #PV #LV #SN Attr VSize VFree
centos 1 3 0 wz--n- <59.00g 4.00m
systemvg 2 1 0 wz--n- 1.99g 1016.00m
// 通过lsblk命令也可以看到
[root@www ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 60G 0 disk
├─sda1 8:1 0 1G 0 part /boot
└─sda2 8:2 0 59G 0 part
├─centos-root 253:0 0 38.3G 0 lvm /
├─centos-swap 253:1 0 2G 0 lvm [SWAP]
└─centos-home 253:2 0 18.7G 0 lvm /home
sdb 8:16 0 10G 0 disk
├─sdb1 8:17 0 1G 0 part
│ └─systemvg-vo 253:3 0 1G 0 lvm
├─sdb2 8:18 0 1G 0 part
│ └─systemvg-vo 253:3 0 1G 0 lvm
├─sdb3 8:19 0 1G 0 part
├─sdb4 8:20 0 1K 0 part
└─sdb5 8:21 0 1G 0 part
sdc 8:32 0 10G 0 disk
├─sdc1 8:33 0 953.7M 0 part
└─sdc2 8:34 0 3.7G 0 part
sr0 11:0 1 4.3G 0 rom /mydvd
[root@www ~]#
// 通过挂载来使用逻辑卷
[root@www ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/centos-root 39G 3.7G 35G 10% /
devtmpfs 475M 0 475M 0% /dev
tmpfs 487M 0 487M 0% /dev/shm
tmpfs 487M 7.7M 479M 2% /run
tmpfs 487M 0 487M 0% /sys/fs/cgroup
/dev/sr0 4.3G 4.3G 0 100% /mydvd
/dev/sda1 1014M 133M 882M 14% /boot
/dev/mapper/centos-home 19G 33M 19G 1% /home
tmpfs 98M 0 98M 0% /run/user/0
[root@www ~]# mkdir /mylv
[root@www ~]# mount /dev/systemvg/vo /mylv/
[root@www ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/centos-root 39G 3.7G 35G 10% /
devtmpfs 475M 0 475M 0% /dev
tmpfs 487M 0 487M 0% /dev/shm
tmpfs 487M 7.7M 479M 2% /run
tmpfs 487M 0 487M 0% /sys/fs/cgroup
/dev/sr0 4.3G 4.3G 0 100% /mydvd
/dev/sda1 1014M 133M 882M 14% /boot
/dev/mapper/centos-home 19G 33M 19G 1% /home
tmpfs 98M 0 98M 0% /run/user/0
/dev/mapper/systemvg-vo 1014M 33M 982M 4% /mylv
[root@www ~]#
三、卷组和逻辑卷的扩展
[root@www ~]# vgs
VG #PV #LV #SN Attr VSize VFree
centos 1 3 0 wz--n- <59.00g 4.00m
systemvg 2 1 0 wz--n- 1.99g 1016.00m
[root@www ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
home centos -wi-ao---- <18.70g
root centos -wi-ao---- <38.30g
swap centos -wi-ao---- 2.00g
vo systemvg -wi-ao---- 1.00g
// 1.扩展卷组的空间
[root@www ~]# vgextend systemvg /dev/sdb3 /dev/sdb5
Physical volume "/dev/sdb3" successfully created.
Physical volume "/dev/sdb5" successfully created.
Volume group "systemvg" successfully extended
[root@www ~]# vgs
VG #PV #LV #SN Attr VSize VFree
centos 1 3 0 wz--n- <59.00g 4.00m
systemvg 4 1 0 wz--n- 3.98g 2.98g
[root@www ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
home centos -wi-ao---- <18.70g
root centos -wi-ao---- <38.30g
swap centos -wi-ao---- 2.00g
vo systemvg -wi-ao---- 1.00g
[root@www ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 centos lvm2 a-- <59.00g 4.00m
/dev/sdb1 systemvg lvm2 a-- 1020.00m 0
/dev/sdb2 systemvg lvm2 a-- 1020.00m 1016.00m
/dev/sdb3 systemvg lvm2 a-- 1020.00m 1020.00m
/dev/sdb5 systemvg lvm2 a-- 1020.00m 1020.00m
// 2.扩展逻辑卷的空间
[root@www ~]# vgs
VG #PV #LV #SN Attr VSize VFree
centos 1 3 0 wz--n- <59.00g 4.00m
systemvg 4 1 0 wz--n- 3.98g 2.98g
[root@www ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
home centos -wi-ao---- <18.70g
root centos -wi-ao---- <38.30g
swap centos -wi-ao---- 2.00g
vo systemvg -wi-ao---- 1.00g
[root@www ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/centos-root 39G 3.7G 35G 10% /
devtmpfs 475M 0 475M 0% /dev
tmpfs 487M 0 487M 0% /dev/shm
tmpfs 487M 7.7M 479M 2% /run
tmpfs 487M 0 487M 0% /sys/fs/cgroup
/dev/sr0 4.3G 4.3G 0 100% /mydvd
/dev/sda1 1014M 133M 882M 14% /boot
/dev/mapper/centos-home 19G 33M 19G 1% /home
tmpfs 98M 0 98M 0% /run/user/0
/dev/mapper/systemvg-vo 1014M 33M 982M 4% /mylv
[root@www ~]#
[root@www ~]# lvextend -L 2G /dev/systemvg/vo
Size of logical volume systemvg/vo changed from 1.00 GiB (256 extents) to 2.00 GiB (512 extents).
Logical volume systemvg/vo successfully resized.
[root@www ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/centos-root 39G 3.7G 35G 10% /
devtmpfs 475M 0 475M 0% /dev
tmpfs 487M 0 487M 0% /dev/shm
tmpfs 487M 7.7M 479M 2% /run
tmpfs 487M 0 487M 0% /sys/fs/cgroup
/dev/sr0 4.3G 4.3G 0 100% /mydvd
/dev/sda1 1014M 133M 882M 14% /boot
/dev/mapper/centos-home 19G 33M 19G 1% /home
tmpfs 98M 0 98M 0% /run/user/0
/dev/mapper/systemvg-vo 1014M 33M 982M 4% /mylv
// 扩展后，我们需要刷新文件系统
[root@www ~]# xfs_growfs /dev/systemvg/vo
meta-data=/dev/mapper/systemvg-vo isize=512 agcount=4, agsize=65536 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0 spinodes=0
data = bsize=4096 blocks=262144, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal bsize=4096 blocks=2560, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
data blocks changed from 262144 to 524288
[root@www ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/centos-root 39G 3.7G 35G 10% /
devtmpfs 475M 0 475M 0% /dev
tmpfs 487M 0 487M 0% /dev/shm
tmpfs 487M 7.7M 479M 2% /run
tmpfs 487M 0 487M 0% /sys/fs/cgroup
/dev/sr0 4.3G 4.3G 0 100% /mydvd
/dev/sda1 1014M 133M 882M 14% /boot
/dev/mapper/centos-home 19G 33M 19G 1% /home
tmpfs 98M 0 98M 0% /run/user/0
/dev/mapper/systemvg-vo 2.0G 33M 2.0G 2% /mylv
[root@www ~]#
四、逻辑卷的删除
// 逻辑卷的删除
// 删除卷组的前提：基于此卷组创建的所有逻辑卷，要全部删除
// 删除逻辑卷的前提：不能删除正在挂载使用的逻辑卷
[root@www ~]# lvremove /dev/systemvg/vo
Logical volume systemvg/vo contains a filesystem in use.
// 我们需要先卸载正在挂载使用的逻辑卷
[root@www ~]# umount /mylv/
// 此时就能删除成功
[root@www ~]# lvremove /dev/systemvg/vo
Do you really want to remove active logical volume systemvg/vo? [y/n]: y
Logical volume "vo" successfully removed
// 删除卷组，我们输入y即可
[root@www ~]# vgremove systemvg
[root@www ~]# vgs
VG #PV #LV #SN Attr VSize VFree
centos 1 3 0 wz--n- <59.00g 4.00m
[root@www ~]#