LVM學習筆記
阿新 • • 發佈：2017-07-02
linux
/* */ ~]# vgdisplay
--- Volume group ---
VG Name ol
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 4
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 3
Open LV 3
Max PV 0
Cur PV 1
Act PV 1
VG Size 99.00 GiB
PE Size 4.00 MiB
Total PE 25343
Alloc PE / Size 25342 / 98.99 GiB
Free PE / Size 1 / 4.00 MiB
VG UUID 0fRWww-EJtp-StyQ-Vt2v-IOvU-9kkT-V0spMP
--- Volume group ---
VG Name test_vg
System ID
Format lvm2
Metadata Areas 3
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 3
Act PV 3
VG Size 2.99 GiB
PE Size 4.00 MiB
Total PE 765
Alloc PE / Size 0 / 0
Free PE / Size 765 / 2.99 GiB
VG UUID 57ta1G-U2St-BY8s-XU1T-MZHN-NWjC-EucYKQLVM：Logical Volume Manager
一、創建、刪除物理卷
pvcreate /PATH/TO/PV
pvremove /PATH/TO/PV
pvdisplay
pvs
[[email protected] ~]# pvcreate /dev/sdb{1,2,3,5}
Physical volume "/dev/sdb1" successfully created.
Physical volume "/dev/sdb2" successfully created.
Physical volume "/dev/sdb3" successfully created.
二、創建、刪除卷組
vgcreate VG_NAME /PATH/TO/PV
vgremove VG_NAME 刪除卷組
vgdisplay 顯示詳細信息
vgs 顯示卷組名、物理卷個數、容量大小（信息相較簡略）
-s #: PE大小，默認為4MB
[[email protected] ~]# vgcreate test_vg /dev/sdb{1,2,3}
Volume group "test_vg" successfully created
[[email protected]三、創建邏輯卷
[[email protected] ~]# vgcreate test_vg /dev/sdb{1,2,3}
Volume group "test_vg" successfully createdlvcreate -n LV_NAME -L（邏輯卷總大小） #G VG_NAME | -l （邏輯卷裏PE個數）#G VG_NAME
[[email protected] ~]# lvcreate -n test_lv -L 2G test_vg Logical volume "test_lv" created. [[email protected] ~]# lvs LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert home ol -wi-ao---- 45.12g root ol -wi-ao---- 50.00g swap ol -wi-ao---- 3.88g test_lv test_vg -wi-a----- 1.56g
四、格式化為ext3
[[email protected] ~]# mke2fs -j /dev/test_vg/test_lv
mke2fs 1.42.9 (28-Dec-2013)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
102544 inodes, 409600 blocks
20480 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=419430400
13 block groups
32768 blocks per group, 32768 fragments per group
7888 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912
Allocating group tables: done
Writing inode tables: done
Creating journal (8192 blocks): done
Writing superblocks and filesystem accounting information: done五、擴展卷組
[[email protected] ~]# vgextend test_vg /dev/sdb5 Volume group "test_vg" successfully extended
六、擴展邏輯卷
lvextend -L [+]# /PATH/TO/LV
[[email protected] ~]# lvextend -L +500M /dev/test_vg/test_lv Rounding size to boundary between physical extents: 504.00 MiB. Size of logical volume test_vg/test_lv changed from 1.56 GiB (200 extents) to 2.05 GiB (263 extents). Logical volume test_vg/test_lv successfully resized.
七、指定文件系統
resize2fs /PATH/TO/PV 3G
[[email protected] ~]# resize2fs -p /dev/test_vg/test_lv resize2fs 1.42.9 (28-Dec-2013) Resizing the filesystem on /dev/test_vg/test_lv to 538624 (4k) blocks. Begin pass 1 (max = 4) Extending the inode table XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX The filesystem on /dev/test_vg/test_lv is now 538624 blocks long.
八、縮減邏輯卷
註意事項：
1.不能在線縮減，得先卸載
2.確保縮減後的空間大小依然能存儲原有的所有數據
3.在縮減之前應該先強行檢查文件，以確保文件系統處於一致性狀態
[[email protected] ~]# df -h Filesystem Size Used Avail Use% Mounted on devtmpfs 1.8G 0 1.8G 0% /dev tmpfs 1.8G 8.0K 1.8G 1% /dev/shm tmpfs 1.8G 9.1M 1.8G 1% /run tmpfs 1.8G 0 1.8G 0% /sys/fs/cgroup /dev/mapper/ol-root 50G 8.7G 42G 18% / /dev/sda1 1014M 341M 674M 34% /boot /dev/mapper/ol-home 46G 37M 46G 1% /home tmpfs 368M 8.0K 368M 1% /run/user/0 /dev/sr0 4.4G 4.4G 0 100% /run/media/root/OL-7.3 Server.x86_64 /dev/mapper/test_vg-test_lv 2.0G 2.4M 1.9G 1% /mnt [[email protected] ~]# umount /mnt [[email protected] ~]# e2fsck -f /dev/test_vg/test_lv （強制檢查文件系統） e2fsck 1.42.9 (28-Dec-2013) 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/test_vg/test_lv: 11/134096 files (0.0% non-contiguous), 17228/538624 blocks [[email protected] ~]# resize2fs /dev/test_vg/test_lv 300M（文件系統先縮小300M） resize2fs 1.42.9 (28-Dec-2013) Resizing the filesystem on /dev/test_vg/test_lv to 76800 (4k) blocks. The filesystem on /dev/test_vg/test_lv is now 76800 blocks long. [[email protected] ~]# lvreduce -L 300M /dev/test_vg/test_lv （物理空間再縮小300M） Rounding size to boundary between physical extents: 304.00 MiB. WARNING: Reducing active logical volume to 304.00 MiB. THIS MAY DESTROY YOUR DATA (filesystem etc.) Do you really want to reduce test_vg/test_lv? [y/n]: y Size of logical volume test_vg/test_lv changed from 2.05 GiB (263 extents) to 304.00 MiB (38 extents). Logical volume test_vg/test_lv successfully resized.
九、快照卷
知識點：
1、生命周期為整個數據時長；在這段時長內，數據的增長量不能超出快照卷大小；
2、快照卷應該是只讀的；
3、跟原卷在同一卷組內；
[[email protected] ~]# lvcreate -n test_plv -L 500M -p r /dev/test_vg Rounding up size to full physical extent 504.00 MiB WARNING: Logical volume test_vg/test_plv not zeroed. Logical volume "test_plv" created.
LVM學習筆記