lvcreate.1m (2010 09)

l
lvcreate(1M) lvcreate(1M)
-D distributed Set the distributed allocation policy. distributed can have one of the fol-
lowing values:
y Turn on distributed allocation.
n Turn off distributed allocation. This is the default.
When the distributed allocation policy is turned on, only one free extent
is allocated from the first available physical volume. The next free
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. This is the default.
The distributed allocation policy REQUIRES the PVG-strict allocation
policy (
-s g) to ensure that mirrors of distributed extents do not overlap
(for maximum availability).
lvcreate (1M) will obtain the list of available physical volumes from
/etc/lvmpvg. See vgextend (1M) for more information on physical
volume groups and /etc/lvmpvg.
When a logical volume with distributed extents is mirrored, the resulting
layout is commonly referred to as EXTENT-BASED MIRRORED
STRIPES.
Note that EXTENT-BASED MIRRORED STRIPES can be created
without the distributed allocation policy by adding one extent at a time to
the desired physical volumes through lvextend (1M).
The distributed allocation policy is incompatible with the striped
scheduling policy (
-i stripes) and the contiguous allocation policy (-C
y).
The lvchange (1M) command can be used to assign the distributed alloca-
tion policy to an existing logical volume.
See lvdisplay (1M) for display values.
See EXAMPLES.
-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.
-i stripes Set the number of disks to stripe across, for the new logical volume.
stripes must be at least 2 and no greater than a volume group version-
dependent maximum; use the lvmadm command to determine the max-
imum supported stripes for the volume group version.
If
-i is provided and -I is not, the stripe size is set to 8 kilobytes.
The
-i option is not applicable for snapshot volumes.
-I stripe_size Set the size in kilobytes of the stripe. stripe_size should be a power of 2.
stripe_size must be at least 4 and no greater than a volume group
version-dependent maximum; use the lvmadm command to determine
the maximum supported stripe_size for the volume group version.
If
-I is provided and -i is not, the command will fail and return an
error. Stripe size should be a value less than or equal to physical extent
size and must be specified with the -i option.
The
-I option is not applicable for snapshot volumes.
4 Hewlett-Packard Company − 4 − HP-UX 11i Version 3: September 2010