LVM logical Volume Management under Linux
Partition [root@db01 ~] # fdisk-l
Disk / dev/sda: 10.7 GB, 10737418240 bytes
255 heads, 63 sectors/track, 1305 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/ dev/sda1 * 1 13 104391 83 Linux
/ dev/sda2 14 1305 10377990 8e Linux LVM
Disk / dev/sdb: 5368 MB, 5368709120 bytes
255 heads, 63 sectors/track, 652 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk / dev/sdb doesn't contain a valid partition table
[root@db01 ~] #
[root@db01 ~] # fdisk / dev/sdb
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel. 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)
Command (m for help): M
Command action
A toggle a bootable flag
B edit bsd disklabel
C toggle the dos compatibility flag
D delete a partition
L list known partition types
M print this menu
N add a new partition
O create a new empty DOS partition table
P print the partition table
Q quit without saving changes
S create a new empty Sun disklabel
T change a partition's system id
U change display/entry units
V verify the partition table
W write table to disk and exit
X extra functionality (experts only)
Command (m for help): n
Command action
E extended
P primary partition (1-4)
P
Partition number (1-4): 1
First cylinder (1,652, default 1):
Using default value 1
Last cylinder or + size or + sizeM or + sizeK (1-652,652):
Using default value 652
Command (m for help): W
The partition table has been altered!
Calling ioctl () to re-read partition table.
Syncing disks.
[root@db01 ~] #
[root@db01 ~] # fdisk-l
Disk / dev/sda: 10.7 GB, 10737418240 bytes
255 heads, 63 sectors/track, 1305 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/ dev/sda1 * 1 13 104391 83 Linux
/ dev/sda2 14 1305 10377990 8e Linux LVM
Disk / dev/sdb: 5368 MB, 5368709120 bytes
255 heads, 63 sectors/track, 652 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/ dev/sdb1 1 652 5237158 + 83 Linux
[root@db01 ~] #
[root@db01 ~] #
[root@db01 ~] # pvcreate / dev/sdb1
Physical volume "/ dev/sdb1" successfully created
[root@db01 ~] #
[root@db01 ~] # vgcreate testvg / dev/sdb1
/ dev/hdc: open failed: No medium found
Volume group "testvg" successfully created
[root@db01 ~] #
[root@db01 ~] # vgdisplay
-Volume group
VG Name testvg
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 4.99 GB
PE Size 4.00 MB
Total PE 1278
Alloc PE / Size 0 / 0
Free PE / Size 1278 / 4.99 GB
VG UUID SMGvyj-hKdO-ILqF-Z9y3-1qPb-WHyQ-K7zN5d
-Volume group
VG Name VolGroup00
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 3
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 2
Max PV 0
Cur PV 1
Act PV 1
VG Size 9.88 GB
PE Size 32.00 MB
Total PE 316
Alloc PE / Size 316 / 9.88 GB
Free PE / Size 0 / 0
VG UUID wH67cF-9Z6s-YEXC-yf0U-q0ep-NK0g-7gC25V
[root@db01 ~] #
[root@db01] # lvcreate-L100-n lv_test01 testvg
Logical volume "lv_test01" created
[root@db01 ~] #
[root@db01] # df-h
Filesystem Size Used Avail Use% Mounted on
/ dev/mapper/VolGroup00-LogVol00
7.7G 4.3G 3.0G 60% /
/ dev/sda1 99m 12m 82m 13% / boot
Tmpfs 506m 0506m 0% / dev/shm
Create a new lv
Create pv
Pvcreate / dev/sdb1
Create vg
Vgcreate testvg / dev/sdb1
Create a lv in M
Lvcreate-L100-n lv_test01 testvg
Or specify the number of pe
Lvcreate-l45230 testvg-n lv_test01
Extended lv
Add sdc2 extensions to testvg
Vgextend testvg / dev/sdc2
Extend lv_test01 to 12G
Lvextend-L12G / dev/testvg/lv_test01
Increase lv_test01 by 1G
Lvextend-L + 1G / dev/testvg/lv_test01
File system
Create a file system in ext3 format
Mkfs.ext3 / dev/testvg/lv_test01
Or
Mkfs-t ext3 / dev/testvg/lv_test01
Mount to / mount_test
Mount / dev/testvg/lv_test01 / mount_test
After extending lv, you need to resize the file system (facing ext2, ext3, ext4, etc.)
Df-h-T view file system format
E2fsck-f / dev/testvg/lv_test01-- can not be executed
Resize2fs-p / dev/testvg/lv_test01
If the file system format is reiserfs
Resize_reiserfs-f / dev/testvg/lv_test01
Delete
Delete the pv,pvdisplay in testvg to confirm that pv is in use
Vgreduce testvg / dev/hda1
Delete lv
Umount / dev/testvg/lv_test01
Lvremove / dev/testvg/lv_test01
Activate vg
Deactivate vg
Vgchange-an / dev/vg001
Activate vg
Vgchange-ay vg001
