Chapter 10. LVM Configuration
LVM can be configured during the graphical installation of Red Hat Linux or during
a kickstart installation. You can use the utilities from the
lvm package to create your LVM configuration, but
these instructions will focus on using Disk
Druid during the Red Hat Linux installation to complete this task.
Read Chapter 4 first to learn about LVM. An overview
of the steps required to configure LVM:
Create physical volumes from the hard
drives.
Create volume groups from the physical
volumes.
Create logical volumes from the volume
groups and assign the logical volumes mount points.
 | Note |
|---|
| | You can only edit LVM volume groups in GUI installation mode. In
text installation mode, you can assign mount points to existing
logical volumes.
|
To create a logical volume group with logical volumes during the Red Hat Linux
installation:
On the Disk Partitioning Setup screen, select
Manually partition with Disk Druid.
Select New.
You will not be able to enter a mount point (you will be able to
do that once you have created your volume group).
Select physical volume (LVM) from the
Filesystem Type pull-down menu as shown in Figure 10-1.
A physical volume must be constrained to one drive. For
, select the drive on which
the physical volume will be created. If you have multiple drives, all
drives will be selected here, and you must deselect all but one drive.
Enter the size that you want the physical volume to be.
Select Fixed size to make the physical volume
the specified size, select Fill all space up to
(MB) and enter a size in MBs to give range for the physical
volume size, or select Fill to maximum allowable
size to make it grow to fill all available space on the
hard disk. If you make more than one growable, they will share the
available free space on the disk.
Select Force to be a primary partition if you
want the partition to be a primary partition.
Select Check for bad blocks if you want the
installation program to check for bad blocks on the hard drive before
formatting it.
Click OK to return to the main screen.
Repeat these step to create as many physical volumes as needed for your
LVM setup. For example, if you want the volume group to span over
more than one drive, create a physical volume on each of the drives.
 | Warning |
|---|
| | The /boot partition can not be on a
volume group because the boot loader can not read it. If you want to have
your root partition on a logical volume, you will need to create a
separate /boot partition which is not a part of a
volume group.
|
Once all the physical volumes are created, follow these steps:
Click the LVM button to collect the
physical volumes into volume groups. A volume group is basically a
collection of physical volumes. You can have multiple logical volume
groups, but a physical volume can only be in one volume group.
| Note |
|---|
| | There is overhead disk space reserved in the logical volume
group. The summation of the physical volumes may not equal the size
of the volume group; however, the size of the logical volumes shown is
correct. |
Change the Volume Group Name if
desired.
All logical volumes inside the volume group must be allocated in
physical extent units. By default, the physical
extent is set to 4 MB; thus, logical volume sizes must be divisible by
4 MBs. If you enter a size that is not a unit of 4 MBs, the
installation program will automatically select the closest size in
units of 4 MBs. It is not recommended that you change this setting.
Select which physical volumes to use for the volume group.
Create logical volumes with mount points such as
/home. Remember that /boot
can not be a logical volume. To add a logical volume, click the
Add button in the Logical
Volumes section. A dialog window as shown in Figure 10-3 will appear.
Repeat these steps for each volume group you want to create.
 | Tip |
|---|
| | You may want to leave some free space in the logical volume
group so you can expand the logical volumes later.
|
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