【基础】LVM简单使用 - 扩展缩小LV容量
lv的最大容量和PE的大小有关，每个lv的容量PE x 65536，默认pe=4M，所以最大只有256G。
已设置好的pe大小，之后没法更改。
1、扩展LV容量
a.添加lvm分区(fdisk ---- t ----- l 编号 ----- 8e -----w ---- partprobe)
b.格式分区:mkfs.ext4 /dev/sdb7
c.创建pv物理卷 pvcreate /dev/sdb7
d.把pv添加到vg vgextend lvmvmhard /dev/sdb7
e.扩展lv容量 lvextend -L +2G /dev/lvmvmhard/lvmlv1
f.重设文件系统大小 resize2fs /dev/lvmvmhard/lvmlv1
[root@kvm /]# pvs PV VG Fmt Attr PSize PFree /dev/sdb5 lvmvmhard lvm2 a-- 1.87g 684.00m /dev/sdb6 lvmvmhard lvm2 a-- 2.80g 0 /dev/sdb7 lvm2 a-- 4.67g 4.67g
[root@kvm /]# vgdisplay --- Volume group --- VG Name lvmvmhard System ID Format lvm2 Metadata Areas 2 Metadata Sequence No 2 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 4.67 GiB PE Size 4.00 MiB Total PE 1195 Alloc PE / Size 1024 / 4.00 GiB Free PE / Size 171 / 684.00 MiB VG UUID yWRR2f-3SZx-MZnc-gCz1-zwYT-KH3D-FdOiHk
把sdb7添加到 lvmvmhard卷组中
[root@kvm /]# vgextend lvmvmhard /dev/sdb7 Volume group "lvmvmhard" successfully extended
查看vgdisplay，vgsize total pe已改变，增加了不少。
[root@kvm /]# pvs PV VG Fmt Attr PSize PFree /dev/sdb5 lvmvmhard lvm2 a-- 1.87g 684.00m /dev/sdb6 lvmvmhard lvm2 a-- 2.80g 0 /dev/sdb7 lvmvmhard lvm2 a-- 4.66g 4.66g /dev/sdb8 lvm2 a-- 10.00g 10.00g ----------------------------------------------------------- [root@kvm /]# vgdisplay --- Volume group --- VG Name lvmvmhard System ID Format lvm2 Metadata Areas 3 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 3 Act PV 3 VG Size 9.33 GiB PE Size 4.00 MiB Total PE 2389 Alloc PE / Size 1024 / 4.00 GiB Free PE / Size 1365 / 5.33 GiB VG UUID yWRR2f-3SZx-MZnc-gCz1-zwYT-KH3D-FdOiHk
使用lvextend 为lvmlv1（lv）扩容。
[root@kvm /]# lvextend -L +2G /dev/lvmvmhard/lvmlv1
Extending logical volume lvmlv1 to 6.00 GiB
Logical volume lvmlv1 successfully resized
df -h lvmlv1还是大小还是原来的，并没有增加。
[root@kvm /]# pvscan
PV /dev/sdb5 VG lvmvmhard lvm2 [1.87 GiB / 0 free]
PV /dev/sdb6 VG lvmvmhard lvm2 [2.80 GiB / 0 free]
PV /dev/sdb7 VG lvmvmhard lvm2 [4.66 GiB / 3.33 GiB free]
PV /dev/sdb8 lvm2 [10.00 GiB]
Total: 4 [19.34 GiB] / in use: 3 [9.33 GiB] / in no VG: 1 [10.00 GiB]
[root@kvm /]# lvdisplay
--- Logical volume ---
LV Path /dev/lvmvmhard/lvmlv1
LV Name lvmlv1
VG Name lvmvmhard
LV UUID Rlx8Lk-mZQU-WniC-Rw9B-OCaW-r2q9-q3KrYL
LV Write Access read/write
LV Creation host, time kvm, 2014-04-11 21:00:58 +0800
LV Status available
# open 1
LV Size 6.00 GiB
Current LE 1536
Segments 3
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
[root@kvm /]# vgdisplay
--- Volume group ---
VG Name lvmvmhard
System ID
Format lvm2
Metadata Areas 3
Metadata Sequence No 4
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 1
Open LV 1
Max PV 0
Cur PV 3
Act PV 3
VG Size 9.33 GiB
PE Size 4.00 MiB
Total PE 2389
Alloc PE / Size 1536 / 6.00 GiB
Free PE / Size 853 / 3.33 GiB
VG UUID yWRR2f-3SZx-MZnc-gCz1-zwYT-KH3D-FdOiHk
[root@kvm /]#
[root@kvm /]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 117G 11G 100G 10% /
tmpfs 242M 76K 242M 1% /dev/shm
/dev/mapper/lvmvmhard-lvmlv1 4.0G 167M 3.6G 5% /lvlvm1
/dev/sr0 602M 602M 0 100% /media/GRTMPVOL_CN
[root@kvm /]#
[root@kvm /]# resize2fs /dev/lvmvmhard/lvmlv1
使用resize2fs重设大小
[root@kvm /]# resize2fs /dev/lvmvmhard/lvmlv1 resize2fs 1.41.12 (17-May-2010) Filesystem at /dev/lvmvmhard/lvmlv1 is mounted on /lvlvm1; on-line resizing required old desc_blocks = 1, new_desc_blocks = 1 Performing an on-line resize of /dev/lvmvmhard/lvmlv1 to 1572864 (4k) blocks. The filesystem on /dev/lvmvmhard/lvmlv1 is now 1572864 blocks long. [root@kvm /]# df -h Filesystem Size Used Avail Use% Mounted on /dev/sda2 117G 11G 100G 10% / tmpfs 242M 76K 242M 1% /dev/shm /dev/mapper/lvmvmhard-lvmlv1 6.0G 167M 5.5G 3% /lvlvm1 /dev/sr0 602M 602M 0 100% /media/GRTMPVOL_CN [root@kvm /]#
2、缩小LV容量
a.umount分区 umount /dev/lvmvmhard/lvmlv1
b.调整文件系统大小为5G(即缩小1G空间) resize2fs /dev/lvmvmhard/lvmlv1 5G
c.把lv空间缩小到5G(要和文件系统一样大小) lvreduce -L 5G /dev/lvmvmhard/lvmlv1
d.重新挂载分区 mount /dev/lvmvmhard/lvmlv1 /lvlvm1/
[root@kvm /]# lvdisplay
--- Logical volume ---
LV Path /dev/lvmvmhard/lvmlv1
LV Name lvmlv1
VG Name lvmvmhard
LV UUID Rlx8Lk-mZQU-WniC-Rw9B-OCaW-r2q9-q3KrYL
LV Write Access read/write
LV Creation host, time kvm, 2014-04-11 21:00:58 +0800
LV Status available
# open 1
LV Size 6.00 GiB
Current LE 1536
Segments 3
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
[root@kvm /]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 117G 11G 100G 10% /
tmpfs 242M 76K 242M 1% /dev/shm
/dev/mapper/lvmvmhard-lvmlv1 6.0G 167M 5.5G 3% /lvlvm1
/dev/sr0 602M 602M 0 100% /media/GRTMPVOL_CN
[root@kvm /]# umount /dev/lvmvmhard/lvmlv1
[root@kvm /]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 117G 11G 100G 10% /
tmpfs 242M 76K 242M 1% /dev/shm
/dev/sr0 602M 602M 0 100% /media/GRTMPVOL_CN
[root@kvm /]# resize2fs --help
resize2fs 1.41.12 (17-May-2010)
resize2fs: invalid option -- '-'
Usage: resize2fs [-d debug_flags] [-f] [-F] [-M] [-P] [-p] device [new_size]
[root@kvm /]# resize2fs /dev/lvmvmhard/lvmlv1 5GB
resize2fs 1.41.12 (17-May-2010)
resize2fs: Invalid new size: 5GB
[root@kvm /]# resize2fs /dev/lvmvmhard/lvmlv1 5GB
resize2fs 1.41.12 (17-May-2010)
resize2fs: Invalid new size: 5GB
[root@kvm /]# resize2fs /dev/lvmvmhard/lvmlv1 5000MB
resize2fs 1.41.12 (17-May-2010)
resize2fs: Invalid new size: 5000MB
[root@kvm /]# resize2fs /dev/lvmvmhard/lvmlv1 5G
resize2fs 1.41.12 (17-May-2010)
Resizing the filesystem on /dev/lvmvmhard/lvmlv1 to 1310720 (4k) blocks.
The filesystem on /dev/lvmvmhard/lvmlv1 is now 1310720 blocks long.
[root@kvm /]# lvreduce -L 5G /dev/lvmvmhard/lvmlv1
WARNING: Reducing active logical volume to 5.00 GiB
THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce lvmlv1? [y/n]: y
Reducing logical volume lvmlv1 to 5.00 GiB
Logical volume lvmlv1 successfully resized
[root@kvm /]# mount /dev/lvmvmhard/lvmlv1 /m
media/ misc/ mnt/ mytest/
[root@kvm /]# mount /dev/lvmvmhard/lvmlv1 /m
media/ misc/ mnt/ mytest/
[root@kvm /]# mount /dev/lvmvmhard/lvmlv1 /l
lib/ lib64/ lost+found/ lvlvm1/
[root@kvm /]# mount /dev/lvmvmhard/lvmlv1 /lvlvm1/
[root@kvm /]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 117G 11G 100G 10% /
tmpfs 242M 76K 242M 1% /dev/shm
/dev/sr0 602M 602M 0 100% /media/GRTMPVOL_CN
/dev/mapper/lvmvmhard-lvmlv1 5.0G 167M 4.6G 4% /lvlvm1
[root@kvm /]# cd /lvlvm1/
[root@kvm lvlvm1]# ls
etc lost+found