lvreduce.1m (2010 09)

l
lvreduce(1M) lvreduce(1M)
NAME
lvreduce - decrease space allocation or the number of mirror copies of logical volumes
SYNOPSIS
/usr/sbin/lvreduce
[-A autobackup ][-f]
-l le_number lv_path
/usr/sbin/lvreduce
[-A autobackup ][-f
] -L lv_size lv_path
/usr/sbin/lvreduce
[-A autobackup ] -m mirror_copies lv_path [pv_path ...]
/usr/sbin/lvreduce
[-A autobackup ] -k -m
mirror_copies lv_path pvkey ...
Remarks
Mirrored disk operations require the installation of the optional HP MirrorDisk/UX software, which is not
included in the standard HP-UX operating system.
DESCRIPTION
The
lvreduce command reduces the number of logical extents allocated to a logical volume specified by
lv_path . The excess physical extents in the logical volume and any mirror copies are deallocated.
Alternatively, it reduces the number of mirror copies in the logical volume. The physical extents that
comprise the deleted mirror copy or copies are deallocated. If pv_path ... is specified, the mirror or mir-
rors to be removed will be deallocated from those specific physical volumes.
lvreduce asks for confirmation before deallocating logical extents if the -f option is omitted.
The
lvreduce command can be used to reduce the number of logical extents allocated to an original log-
ical volume on a snapshot tree only if all its snapshot logical volumes are fully allocated snapshot logical
volumes. Note that it is prohibited to reduce the number of logical extents allocated to the original logical
volume on a snapshot tree if at least one space efficient snapshot is associated with it. Alternatively, the
lvreduce command can be used to reduce the number of mirror copies of the original logical volume on
a snapshot tree.
Snapshot Volume Considerations
Note that it is prohibited to reduce the number of logical extents or the number of mirror copies of any
snapshot logical volume.
Options and Arguments
The -m option and pv_path argument are only meaningful if the optional HP MirrorDisk/UX software has
been installed on the system.
lvreduce recognizes the following options and arguments:
lv_path The block device path name of a logical volume.
pv_path The block device path name of a physical volume.
-A autobackup Set automatic backup for invocation of this command. autobackup can have
one of the following values:
y Automatically back up configuration changes made to the logical volume.
This is the default.
After this command executes, the
vgcfgbackup command (see
vgcfgbackup (1M)) is executed for the volume group to which the logical
volume belongs.
n Do not back up configuration changes.
-f Force reduction of the number of logical extents without first requesting
confirmation.
This option can be dangerous when there is a file system on the lv_path that is
larger than the size that the logical volume is being reduced to. If the file sys-
tem is unmounted, the
-f option forces the reduction of the logical volume
without reducing the file system. The file system becomes corrupt and is not
mountable. If the file system is mounted, lvreduce fails, preventing a
mounted file system from becoming corrupted.
-l le_number Decrease the space allocated to the logical volume, specified in logical extents.
le_number is a decimal value smaller than the current number of logical
extents.
HP-UX 11i Version 3: September 2010 − 1 − Hewlett-Packard Company 1