LVCREATE(8)							  LVCREATE(8)



NAME
       lvcreate - create a logical volume in an existing volume group

SYNOPSIS
       lvcreate	 [--addtag  Tag]  [--alloc AllocationPolicy] [-A/--autobackup
       y/n] [-C/--contiguous y/n] [-d/--debug]	[-h/-?/--help]	[-i/--stripes
       Stripes [-I/--stripesize StripeSize]] {-l/--extents LogicalExtentsNum-
       ber |
	-L/--size LogicalVolumeSize[kKmMgGtT]} [-M/--persistent y/n] [--minor
       minor]	 [-n/--name    LogicalVolumeName]    [-p/--permission	r/rw]
       [-r/--readahead	ReadAheadSectors]  [-R|--regionsize  MirrorLogRegion-
       Size]   [-t/--test]  [-v/--verbose]  [-Z/--zero	y/n]  VolumeGroupName
       [PhysicalVolumePath...]

       lvcreate {-l/--extents LogicalExtentsNumber |
	-L/--size  LogicalVolumeSize[kKmMgGtT]}	 [-c/--chunksize   ChunkSize]
       -s/--snapshot  -n/--name SnapshotLogicalVolumeName OriginalLogicalVol-
       umePath

DESCRIPTION
       lvcreate creates a new logical volume in a volume group (  see  vgcre-
       ate(8),	vgchange(8)  )	by  allocating	logical extents from the free
       physical extent pool of that volume group.  If there  are  not  enough
       free  physical  extents	then  the  volume group can be extended ( see
       vgextend(8) ) with other physical volumes or by reducing existing log-
       ical volumes of this volume group in size ( see lvreduce(8) ).
       The  second  form  supports  the	 creation of snapshot logical volumes
       which keep the contents of the original logical volume for backup pur-
       poses.

OPTIONS
       See lvm for common options.

       -c, --chunksize ChunkSize
	      Power  of	 2 chunk size for the snapshot logical volume between
	      4k and 512k.

       -C, --contiguous y/n
	      Sets or resets the contiguous  allocation	 policy	 for  logical
	      volumes.	Default	 is  no contiguous allocation based on a next
	      free principle.

       -i, --stripes Stripes
	      Gives the number of stripes.  This is equal to  the  number  of
	      physical volumes to scatter the logical volume.

       -I, --stripesize StripeSize
	      Gives  the  number  of  kilobytes	 for  the  granularity of the
	      stripes.
	      StripeSize must be 2^n (n = 2 to 9) for metadata in  LVM1	 for-
	      mat.   For  metadata  in	LVM2 format, the stripe size may be a
	      larger power of 2 but must not exceed the physical extent size.

       -l, --extents LogicalExtentsNumber
	      Gives  the  number  of  logical extents to allocate for the new
	      logical volume.

       -L, --size LogicalVolumeSize[kKmMgGtT]
	      Gives the size to allocate for the new logical volume.  A	 size
	      suffix  of K for kilobytes, M for megabytes, G for gigabytes or
	      T for terabytes is optional.
	      Default unit is megabytes.

       --minor minor
	      Set the minor number.

       -M, --persistent y/n
	      Set to y to make the minor number specified persistent.

       -n, --name LogicalVolumeName
	      The name for the new logical volume.
	      Without this option a default names of "lvol#" will  be  gener-
	      ated  where # is the LVM internal number of the logical volume.

       -p, --permission r/w
	      Set access permissions to read only or read and write.
	      Default is read and write.

       -r, --readahead ReadAheadSectors
	      Set read ahead sector count of this logical volume to  a	value
	      between 2 and 120.  Ignored by device-mapper.

       -R --regionsize MirrorLogRegionSize
	      A	 mirror is divided into regions of this size (in KB), and the
	      mirror log uses this granularity to track which regions are  in
	      sync.

       -s, --snapshot
	      Create a snapshot logical volume (or snapshot) for an existing,
	      so called original logical volume (or origin).  Snapshots	 pro-
	      vide  a  'frozen image' of the contents of the origin while the
	      origin can still be updated. They enable consistent backups and
	      online recovery of removed/overwritten data/files. The snapshot
	      does not need the same amount of storage the origin has.	In  a
	      typical  scenario, 15-20% might be enough. In case the snapshot
	      runs out of storage, use lvextend(8) to grow  it.	 Shrinking  a
	      snapshot	is supported by lvreduce(8) as well. Run lvdisplay(8)
	      on the snapshot in order to check how much data is allocated to
	      it.

       -Z, --zero y/n
	      Controls	zeroing	 of  the  first KB of data in the new logical
	      volume.
	      Default is yes.

	      Warning: trying to mount an unzeroed logical volume  can	cause
	      the system to hang.

Examples
       "lvcreate  -i  3	 -I  8 -L 100 vg00" tries to create a striped logical
       volume with 3 stripes, a stripesize of 8KB and a size of 100MB in  the
       volume  group  named  vg00.  The logical volume name will be chosen by
       lvcreate.

       "lvcreate --size 100m --snapshot --name snap /dev/vg00/lvol1"
       creates a snapshot  logical  volume  named  /dev/vg00/snap  which  has
       access	to   the  contents  of	the  original  logical	volume	named
       /dev/vg00/lvol1 at snapshot logical volume creation time. If the orig-
       inal logical volume contains a file system, you can mount the snapshot
       logical volume on an arbitrary directory in order to access  the	 con-
       tents  of the filesystem to run a backup while the original filesystem
       continues to get updated.


SEE ALSO
       lvm(8),	vgcreate(8),  lvremove(8),  lvrename(8)	 lvextend(8),	lvre-
       duce(8), lvdisplay(8), lvscan(8)



Sistina Software UK		  LVM TOOLS			  LVCREATE(8)

UNIX/Linux commands referenced on this page:

1. free
2. size
3. which
4. lvm
5. make
6. enable
7. as
8. mount
9. at
10. file