lvchange.1m (2010 09)

l
lvchange(1M) lvchange(1M)
extent is allocated from the next available physical volume. Allocation of
free extents proceeds in round-robin order on the list of available physi-
cal volumes.
When the distributed allocation policy is turned off, all available free
extents are allocated from each available physical volume before
proceeding to the next available physical volume.
The distributed allocation policy REQUIRES the PVG-strict allocation
policy (
-s g ) to ensure that mirrors of distributed extents do not over-
lap (for maximum availability).
The distributed allocation policy is incompatible with the striped
scheduling policy (
-i stripes ) and the contiguous allocation policy (
-C
y ).
See lvcreate (1M) for more information on the distributed allocation pol-
icy.
The
-D y option will fail if the existing logical volume has any two con-
secutive logical extents on the same physical volume. To override this
failure, use the -D f option.
If a logical volume with the distributed allocation policy has at least two
consecutive logical extents on the same physical volume, then
lvdisplay (1M) will display the allocation as
partially-
distributed (vs. distributed).
See lvdisplay (1M) for display values.
The
-D option is not applicable for snapshot volumes.
-e auto_prealloc_enabled
Enable/Disable the automatic increase of pre-allocated extents.
auto_prealloc_enabled can have one of the following values:
y Enable the automatic increase of pre-allocated extents. Note that
this feature is enabled only when lvmpud is running.
n Disable the automatic increase of pre-allocated extents.
-M mirror_write_cache Set the Mirror Write Cache flag. This option is allowed only when the
logical volume is not opened.
mirror_write_cache can have one of the following values:
y Set Mirror Write Cache on. Every write to a mirror copy is
recorded in the Mirror Write Cache and written into the Mirror
Consistency Record on the disk if a cache-miss occurs. This allows
LVM to determine whether all mirror copies are identical, even
across system crashes. When the volume group is activated, the
Mirror Consistency Record is used to perform mirror consistency
recovery.
n Set Mirror Write Cache off. Mirror write does not incur an addi-
tional write to the Mirror Consistency Record on the disk.
-p permission Set the access permission. permission can have one of the following
values:
w Set the access permission to read-write.
r Set the access permission to read-only.
-P threshold_value Set the percentage threshold value at which increment messages will be
logged in the systems syslog and/or the automatic increase of pre-
allocated extents will be triggered.
The value ranges between 1 to 100. If the
auto_prealloc_enabled
flag is set (see the -e option), then at the threshold value, the automatic
increase of pre-allocated extents will be triggered. Note that the number
of pre-allocated extents will be incremented by the threshold value. If
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