Last modified: Feb. 27, 2012
Contents
1 - Summary
2 - General information
3 - Physical volumes
4 - Volume groups
5 - Logical volumes
6 - Add space to a volume group
1 - Summary
This guide will show some LVM disk management commands in Red Hat Enterprise
Linux. LVM stands for logical volume manager. A logical volume provides storage
virtualization meaning that it allows you to create a logical storage volume
using multiple physical disks. This has been tested in Red Hat Enterprise Linux
5.
2 - General information
Find out what version of LVM is installed.
# rpm -qa | grep -i lvm
lvm2-2.02.84-6.el5_7.2
system-config-lvm-1.1.5-9.el5
Find out what hard disks the computer has and information about them.
# sudo /sbin/fdisk -l | grep Disk
Password:
Disk /dev/sda: 1000.2 GB, 1000204886016 bytes
Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
# sudo /sbin/hdparm -I /dev/sda | head -n 7 | tail -n 4
Password:
ATA device, with non-removable media
Model Number: Hitachi HUA721010KLA330
Serial Number: GTF000PBGGTADF
Firmware Revision: GKAOA9N1
# sudo /sbin/hdparm -I /dev/sdb | head -n 7 | tail -n 4
Password:
ATA device, with non-removable media
Model Number: Hitachi HUA721010KLA330
Serial Number: GTF000PBGGJSMF
Firmware Revision: GKAOA9N1
Display the local file system disk space usage.
# df -hl
Filesystem Size Used Avail Use% Mounted on
/dev/sda1 93G 15G 75G 17% /
/dev/mapper/VolGroup00-LogVol00
1.7T 400G 1.2T 25% /data
tmpfs 2.0G 0 2.0G 0% /dev/shm
3 - Physical volumes
Scan all disks for physical volumes.
# sudo /sbin/pvscan
Password:
PV /dev/sda3 VG VolGroup00 lvm2 [831.50 GB / 0 free]
PV /dev/sdb1 VG VolGroup00 lvm2 [931.50 GB / 0 free]
Total: 2 [1.72 TB] / in use: 2 [1.72 TB] / in no VG: 0 [0 ]
Display attributes of physical volumes.
# sudo /usr/sbin/pvdisplay /dev/sda3
Password:
--- Physical volume ---
PV Name /dev/sda3
VG Name VolGroup00
PV Size 831.51 GB / not usable 12.53 MB
Allocatable yes (but full)
PE Size (KByte) 32768
Total PE 26608
Free PE 0
Allocated PE 26608
PV UUID wALAIn-1MfU-W1Zc-O70G-0194-2QS5-ddU4tT
# sudo /usr/sbin/pvdisplay /dev/sdb1
Password:
--- Physical volume ---
PV Name /dev/sdb1
VG Name VolGroup00
PV Size 931.51 GB / not usable 11.19 MB
Allocatable yes (but full)
PE Size (KByte) 32768
Total PE 29808
Free PE 0
Allocated PE 29808
PV UUID 45HeHE-EJ0d-AK6A-KWWI-CUgL-4WAx-uXMWZn
4 - Volume groups
Scan all disks for volume groups.
# sudo /sbin/vgscan
Password:
Reading all physical volumes. This may take a while...
Found volume group "VolGroup00" using metadata type lvm2
Display attributes of volume groups.
# sudo /usr/sbin/vgdisplay VolGroup00
Password:
--- Volume group ---
VG Name VolGroup00
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 1.72 TB
PE Size 32.00 MB
Total PE 56416
Alloc PE / Size 56416 / 1.72 TB
Free PE / Size 0 / 0
VG UUID qTyO9u-1keX-a8b0-uAUa-VspH-tysg-Cte41M
5 - Logical volumes
Scan all disks for logical volumes.
# sudo /usr/sbin/lvscan
Password:
ACTIVE '/dev/VolGroup00/LogVol00' [1.72 TB] inherit
Display attributes of logical volume
# sudo /usr/sbin/lvdisplay /dev/VolGroup00/LogVol00
Password:
--- Logical volume ---
LV Name /dev/VolGroup00/LogVol00
VG Name VolGroup00
LV UUID gNvKds-MZIH-ldaO-ghBA-Zk2S-8bUx-Cl9I7x
LV Write Access read/write
LV Status available
# open 1
LV Size 1.72 TB
Current LE 56416
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
6 - Add space to a volume group
We will go through an example of adding more space space to a volume group by
adding a new disk. The first step is create a physical volume.
# sudo /usr/sbin/pvcreate /dev/sdc
Password:
Physical volume "/dev/sdc" successfully created
Next, we want to list the volume groups.
# sudo /sbin/vgscan
Password:
Reading all physical volumes. This may take a while...
Found volume group "VolGroup00" using metadata type lvm2
With the physical volume create, we now need to add it to the volume group.
# sudo /usr/sbin/vgextend VolGroup00 /dev/sdc
Password:
Volume group "VolGroup00" successfully extended
The new physical volume has been added to the volume group and is ready to be
allocated to a logical volume. Display attributes of the new physical volume.
# sudo /usr/sbin/pvdisplay /dev/sdc
Password:
--- Physical volume --
PV Name /dev/sdc
VG Name VolGroup00
PV Size 1.82 TB / not usable 17.09 MB
Allocatable yes
PE Size (KByte) 32768
Total PE 59616
Free PE 59616
Allocated PE 0
PV UUID akTQlv-EM8d-hrYp-t31W-FfbR-Kkds-y5yYXT
Find the name of the logical volume.
# df -hl
Filesystem Size Used Avail Use% Mounted on
/dev/sda1 97G 6.9G 85G 8% /
/dev/mapper/VolGroup00-LogVol00
1.7T 1.5T 168G 90% /data
tmpfs 7.9G 0 7.9G 0% /dev/shm
Next, we extend the size of the logical volume.
# sudo /usr/sbin/lvextend -l+59616 /dev/mapper/VolGroup00-LogVol00
Password:
Rounding up size to full physical extent 1.82 TB
Extending logical volume LogVol00 to 3.52 TB
Logical volume LogVol00 successfully resized
The last step in the process is to resize the file system on the logical volume
so it uses the additional space.
# sudo /sbin/resize2fs /dev/mapper/VolGroup00-LogVol00
Password:
resize2fs 1.39 (29-May-2006)
Filesystem at /dev/mapper/VolGroup00-LogVol00 is mounted on /data; on-line resizing required
Performing an on-line resize of /dev/mapper/VolGroup00-LogVol00 to 943841280 (4k) blocks.
The filesystem on /dev/mapper/VolGroup00-LogVol00 is now 943841280 blocks long.
Finally, do a check to verify that the file system on the logical volume was
resized.
# df -hl
Filesystem Size Used Avail Use% Mounted on
/dev/sda1 97G 7.0G 85G 8% /
/dev/mapper/VolGroup00-LogVol00
3.5T 1.5T 1.9T 44% /data
tmpfs 7.9G 0 7.9G 0% /dev/shm
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