How to create a new logical volume in Red Hat Enterprise 5 Linux.

(1) Click on System – Administration – Logical Volume Manager.

(2) Expand Uninitilized Entities on the left window by clicking on the arrow next to it. You will now see the

available physical disk partitions if there is any. For example /dev/sda or /dev/sdb, sda and sdb are two physical

disk drives.

(3) Display the drive partition information by clicking on the arrow to the left of it. In this example I will use

the drive /dev/sdb. Click on Partiton 1 which is displayed below /dev/sdb, the partion number may differ for you.

The properties of the uninitialized partition 1, /dev/sdb1 will be displayed to the very right of the screen. Below

is an example of what you will see.

Properties of Disk Entry /dev/sdb1 (note this disk entry name, you will need it for later)
Mount Point: Unmounted
Mount Point when Rebooted: None
File System: No Filesystem
Not initialized: Foreign boot partition
SCSI Address: 0:0:1:0
SCSI ID: 360060e800429c400000029c400002b00

(4) On the top menu bar, click on Tools – Initialize Block Device. In the Initialize Block Device window you will

be prompted with the message Enter path of Block Device to initialize. Type the path name /dev/sdb1, and click on

Initialize. When prompted with a warining message “All data on disk entity /dev/sdb1 will be lost! Are you certain

that you wish to initialize it?”, select Yes.

(5) You will now see Partition 1 appear under the category Unallocated Volume in the left window. The properties

of will be displayed in the right window, details as shown below.

Properties for Unallocated Volume /dev/sdb1
Physical Volume Name: /dev/sdb1
Volume Group Name: —
Physical Volume Size: 450.00G
Space Used: 0
Space Free: 450.00G
Total Physical Extents: 0
Allocates Physical Extensts: 0
Attributes: —
PV UUID: 6mp2WC-hk3d-TWAj-dfBf-txin-A9jG-1RrOew
SCSI AddressL 0:0:1:0
SCSI ID: 360060e800429c400000029c400002b00

Select Create new Volume Group. Enter the Volume Group Name as DataVolGroup

(6) In the left window under Volume Groups, select the new volume group DataVolGroup – DataVolumeGroup Physical

View – DataVolumeGroup Logical View. This will display the properties of DataVolumeGroup in the right window.
Click on Create New Logical Volume, this will open up the Create NEw Logical Volume window. Enter the name DataLV

for LV name and for the size of the volume click on Use remaining, this will maximize the volume size.

For Filesystem select Ext3, you have a choice between None, Ext3 and Ext2. The explanation of each filesystem type

is beyond the scope of this article, I may explain that in future posting. Select Mount when rebooted and for

Mount point enter /data.

Click on Ok, you will now see the pop up message “The specified mount point, /data, does not exist. Do you wish to create it?”. Select Yes to continue.

You are done, a reboot may be required. To confirm that the new logical volume was created and mounted after reboot, ether the commands below.

Open a terminal window for the steps below.
mount
/dev/mapper/DataVolGroup-DataLV- on /data type ext3 (rw)

The mount command displays the new logical volume /dev/mapper/DataVolGroup-DataLV mounted on /data, and the filesystem type is ext3. You can access the new partition via the path /data.

To check the size of the new partition, use the df command with the -h option to make it human readable.

df -h
/dev/mapper/DataVolGroup-DataLV 443G 199M 421G 1% /data

Here is what the above output represents.

Filesystem = /dev/mapper/DataVolGroup-DataLV
Size = 443G
Used = 199M
Available = 421G
Use% = 1%
Mounted on = /data