The following section explains how to manually configure LVM for
Red Hat Enterprise Linux. Because there are numerous ways to
manually configure a system with LVM, the following example is
similar to the default configuration done in Section 8.1 Automatic
Partitioning.
On the Disk Partitioning Setup screen,
select Manually partition with Disk
Druid.
In a typical situation, the disk drives are new, or formatted
clean. The following figure, Figure 8-2,
shows both drives as raw devices with no partitioning
configured.
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Warning |
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The /boot/ partition cannot reside on
an LVM volume group because the GRUB boot loader cannot read
it.
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Select New.
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Select /boot from the Mount Point pulldown menu.
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Select ext3 from the File System Type pulldown menu.
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Select only the sda checkbox from the
Allowable Drives area.
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Leave 100 (the default) in the Size (MB) menu.
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Leave the Fixed size (the default) radio
button selected in the Additional Size
Options area.
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Select Force to be a primary partition
to make the partition be a primary partition. A primary partition
is one of the first four partitions on the hard drive. If
unselected, the partition is created as a logical partition. If
other operating systems are already on the system, unselecting this
option should be considered. For more information on primary versus
logical/extended partitions, refer to the appendix section of the
Red Hat Enterprise Linux Installation
Guide.
Refer to Figure 8-3
to verify your inputted values:
Click OK to return to the main screen.
The following figure displays the boot partition correctly set:
Once the boot partition is created, the remainder of all disk
space can be allocated to LVM partitions. The first step in
creating a successful LVM implementation is the creation of the
physical volume(s).
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Select New.
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Select physical volume (LVM) from the
File System Type pulldown menu as shown in
Figure
8-5.
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You cannot enter a mount point yet (you can once you have
created all your physical volumes and then all volume groups).
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A physical volume must be constrained to one drive. For
, select the drive on
which the physical volume are created. If you have multiple drives,
all drives are selected, and you must deselect all but one
drive.
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Enter the size that you want the physical volume to be.
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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 share the
available free space on the disk.
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Select Force to be a primary partition
if you want the partition to be a primary partition.
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Click OK to return to the main
screen.
Repeat these steps 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. The following figure shows both drives completed after
the repeated process:
Once all the physical volumes are created, the volume groups can
be created:
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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.
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Note |
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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.
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Change the Volume Group Name if
desired.
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All logical volumes inside the volume group must be allocated in
physical extent units. By default, the
physical extent is set to 32 MB; thus, logical volume sizes must be
divisible by 32 MBs. If you enter a size that is not a unit of 32
MBs, the installation program automatically selects the closest
size in units of 32 MBs. It is not recommended that you change this
setting.
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Select which physical volumes to use for the volume group.
Create logical volumes with mount points such as /, /home/, and swap
space. Remember that /boot cannot 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 8-8
appears.
Repeat these steps for each volume group you want to create.
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Tip |
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You may want to leave some free space in the logical volume
group so you can expand the logical volumes later. The default
automatic configuration does not do this, but this manual
configuration example does — approximately 1 GB is left as
free space for future expansion.
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Click OK to apply the volume group and
all associated logical volumes.
The following figure shows the final manual configuration:
