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Index for Section 8 |
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Alphabetical listing for L |
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lvreduce(8)
NAME
lvreduce - Decreases the number of physical extents allocated to a logical
volume
SYNOPSIS
/usr/sbin/lvreduce -m MirrorCopies | -l LogicalExtentsNumber [-f]
LogicalVolumePath
DESCRIPTION
Note
This command is no longer supported on Digital UNIX systems.
Features formerly provided by the Logical Volume Manager (LVM)
are now provided by the Logical Storage Manager (LSM). Existing
LVM volumes must be migrated to LSM, using an encapsulation
process. For information about moving LVM volumes to LSM, see the
vollvmencap(8) reference page and the manual Logical Storage
Manager.
The lvreduce command changes either the number of logical extents allocated
to a logical volume specified with the LogicalVolumePath parameter or the
number of physical extents allocated to each logical extent in the logical
volume. The change is determined according to which command flags you use.
FLAGS
-f Forces the reduction of the number of logical extents without
first requesting confirmation. This option can be used only if
the -l flag has been used.
-m MirrorCopies
Sets the number of physical extents allocated for each logical
extent.
MirrorCopies (that is, mirrors) can be either 0 or 1. This means
that beyond the original copy, no other (0) or one (1) mirror
copy will contain the same data as the original copy.
MirrorCopies must be less than the current number of mirrors for
the logical volume. Either this option or the -l option must be
supplied.
-l LogicalExtentsNumber
Decreases the number of logical extents allocated to the
LogicalVolumePath. LogicalExtentsNumber must be less than the
number of logical extents previously allocated to
LogicalVolumePath.
LogicalExtentsNumber represents the new total number of logical
extents within LogicalVolumePath. The change is accomplished by
deallocating the number of logical extents represented by the
difference between the previous number of extents and
LogicalExtentsNumber.
The lvreduce command asks for confirmation if you do not use the
-f flag.
You must use either this option (-l) or the -m option.
EXAMPLES
1. To decrease the number of the logical extents of logical volume lv03
to one hundred, enter:
lvreduce -l 100 /dev/vg01/lv03
2. To get one mirror (that is, two copies) for each logical extent of
logical volume lv05, enter:
lvreduce -m 1 /dev/vg01/lv05
Each logical extent of logical volume lv05 is now singly mirrored.
CAUTIONS
The Logical Volume Manager does not store any information about which
physical extents contain useful data; therefore, using the -l option might
lead to the loss of useful data.
FILES
/usr/sbin/lvreduce
Specifies the command path.
RELATED INFORMATION
Commands: lvcreate(8), lvdisplay(8), lvextend(8), pvchange(8),
pvdisplay(8)