Red Hat GLOBAL FILE SYSTEM 5.0, Руководство администратора

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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
clvmd
daemon. For information, see see
Section 1, “Creating LVM Volumes in a Cluster” .
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
argument in a command, lower-case indicates that units are in multiples
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
lvol0
in a volume group called
vg0
can be specified as
vg0/lvol0
. Where a list of volume groups is required but is left empty, a list of all volume
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
lvdisplay vg0
command will display all the logical volumes in volume group
vg0
.
All LVM commands accept a
-v
argument, which can be entered multiple times to increase the
output verbosity. For example, the following examples shows the default output of the
lvcreate
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
lvcreate
command with the
-v
argument.
Chapter 4.
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