Lvm Administration With Cli Commands; Using Cli Commands - Red Hat LVM ADMINISTRATOR FOR RHEL 4.5 Administrator's Manual

Chapter 4.
LVM Administration with CLI
Commands
This chapter summarizes the individual administrative tasks you can perform with the LVM
Command Line Interface (CLI) commands to create and maintain logical volumes.
Note
If you are creating or modifying an LVM volume for a clustered environment, you
must ensure that you are running the
Section 1, "Creating LVM Volumes in a

1. Using CLI Commands

There are several general features of all LVM CLI commands.
When sizes are required in a command line argument, units can always be specified explicitly. If
you do not specify a unit, then a default is assumed, usually KB or MB. LVM CLI commands do
not accept fractions.
When specifying units in a command line argument, LVM is case-insensitive; specifying M or m
is equivalent, for example, and powers of 2 (multiples of 1024) are used. However, when
specifying the
--units
of 1024 while upper-case indicates that units are in multiples of 1000.
Where commands take volume group or logical volume names as arguments, the full path name
is optional. A logical volume called
. Where a list of volume groups is required but is left empty, a list of all volume
vg0/lvol0
groups will be substituted. Where a list of logical volumes is required but a volume group is
given, a list of all the logical volumes in that volume group will be substituted. For example, the
command will display all the logical volumes in volume group
lvdisplay vg0
All LVM commands accept a
output verbosity. For example, the following examples shows the default output of the
command.
# lvcreate -L 50MB new_vg
Rounding up size to full physical extent 52.00 MB
Logical volume "lvol0" created
The following command shows the output of the
argument in a command, lower-case indicates that units are in multiples
in a volume group called
lvol0
argument, which can be entered multiple times to increase the
-v
daemon. For information, see see
clvmd
Cluster".
vg0
command with the
lvcreate
can be specified as
.
vg0
lvcreate
argument.
-v
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