Provided by: lvm2_2.02.66-4ubuntu7_i386 bug

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]  [--noudevsync]
       [--ignoremonitoring]    [--monitor    {y|n}]    [-i|--stripes   Stripes
       [-I|--stripesize               StripeSize]]               {-l|--extents
       LogicalExtentsNumber[%{VG|PVS|FREE}] |
        -L|--size  LogicalVolumeSize[bBsSkKmMgGtTpPeE]}  [-M|--persistent y|n]
       [--minor   minor]   [-m|--mirrors   Mirrors   [--nosync]   [--mirrorlog
       {disk|core|mirrored}]            [--corelog]           [-R|--regionsize
       MirrorLogRegionSize]]  [-n|--name  LogicalVolumeName]  [-p|--permission
       r|rw]     [-r|--readahead    ReadAheadSectors|auto|none]    [-t|--test]
       [-v|--verbose]         [-Z|--zero         y|n]          VolumeGroupName
       [PhysicalVolumePath[:PE[-PE]]...]

       lvcreate {-l|--extents LogicalExtentsNumber[%{VG|FREE|ORIGIN}] |
        -L|--size     LogicalVolumeSize[bBsSkKmMgGtTpPeE]}     [-c|--chunksize
       ChunkSize]  [--noudevsync]   [--ignoremonitoring]   [--monitor   {y|n}]
       -n|--name           SnapshotLogicalVolumeName          {{-s|--snapshot}
       OriginalLogicalVolumePath     |     [-s|--snapshot]     VolumeGroupName
       --virtualsize VirtualSize}

DESCRIPTION

       lvcreate  creates  a  new  logical  volume  in  a  volume  group  ( see
       vgcreate(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
       logical volumes of this volume group in size ( see  lvreduce(8)  ).  If
       you specify one or more PhysicalVolumes, allocation of physical extents
       will be restricted to these volumes.
       The second form supports the creation of snapshot logical volumes which
       keep the contents of the original logical volume for backup purposes.

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 format.
              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[%{VG|PVS|FREE|ORIGIN}]
              Gives the number of logical extents  to  allocate  for  the  new
              logical   volume.   The  number  can  also  be  expressed  as  a
              percentage of the total space  in  the  Volume  Group  with  the
              suffix  %VG,  as a percentage of the remaining free space in the
              Volume Group with the suffix  %FREE,  as  a  percentage  of  the
              remaining  free  space  for the specified PhysicalVolume(s) with
              the suffix %PVS, or (for a snapshot)  as  a  percentage  of  the
              total  space  in  the  Origin  Logical  Volume  with  the suffix
              %ORIGIN.

       -L, --size LogicalVolumeSize[bBsSkKmMgGtTpPeE]
              Gives the size to allocate for the new logical volume.   A  size
              suffix  of  K for kilobytes, M for megabytes, G for gigabytes, T
              for terabytes, P for petabytes or E for exabytes 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.

       -m, --mirrors Mirrors
              Creates a mirrored logical  volume  with  Mirrors  copies.   For
              example,  specifying  "-m  1" would result in a mirror with two-
              sides; that is, a linear volume plus one copy.

              Specifying  the  optional  argument  --nosync  will  cause   the
              creation  of  the  mirror to skip the initial resynchronization.
              Any data written afterwards will be mirrored, but  the  original
              contents  will  not  be  copied.   This is useful for skipping a
              potentially long and resource intensive initial sync of an empty
              device.

              The  optional  argument --mirrorlog specifies the type of log to
              be used.  The default is disk, which is persistent and  requires
              a  small  amount  of storage space, usually on a separate device
              from the data being mirrored.  Using core means  the  mirror  is
              regenerated by copying the data from the first device again each
              time the device is activated, for example, after  every  reboot.
              Using  "mirrored"  will  create  a persistent log that is itself
              mirrored.

              The optional argument --corelog  is  equivalent  to  --mirrorlog
              core.

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

       --noudevsync
              Disable udev synchronisation. The  process  will  not  wait  for
              notification  from  udev.   It will continue irrespective of any
              possible udev processing in the background.  You should only use
              this if udev is not running or has rules that ignore the devices
              LVM2 creates.

       --monitor y|n
              Start or avoid monitoring a mirrored or snapshot logical  volume
              with  dmeventd,  if  it  is  installed.   If  a device used by a
              monitored mirror reports an I/O error, the  failure  is  handled
              according         to        mirror_image_fault_policy        and
              mirror_log_fault_policy set in lvm.conf.

       --ignoremonitoring
              Make no attempt to interact with dmeventd  unless  --monitor  is
              specified.

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

       -r, --readahead ReadAheadSectors|auto|none
              Set  read ahead sector count of this logical volume.  For volume
              groups with metadata in  lvm1  format,  this  must  be  a  value
              between 2 and 120.  The default value is "auto" which allows the
              kernel to choose a  suitable  value  automatically.   "None"  is
              equivalent to specifying zero.

       -R, --regionsize MirrorLogRegionSize
              A  mirror  is divided into regions of this size (in MB), 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
              provide 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.   Note  that a small amount of the space you allocate to the
              snapshot is used to track the locations of the chunks  of  data,
              so  you  should  allocate  slightly more space than you actually
              need and monitor the rate at which the snapshot data is  growing
              so you can avoid running out of space.

       --virtualsize VirtualSize
              Create  a  sparse  device  of  the given size (in MB by default)
              using a snapshot.   Anything  written  to  the  device  will  be
              returned  when reading from it.  Reading from other areas of the
              device will return  blocks  of  zeros.   It  is  implemented  by
              creating a hidden virtual device of the requested size using the
              zero target.  A suffix of _vorigin is used for this device.

       -Z, --zero y|n
              Controls zeroing of the first KB of  data  in  the  new  logical
              volume.
              Default is yes.
              Volume will not be zeroed if read only flag is set.
              Snapshot volumes are zeroed always.

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

Examples

       "lvcreate -i 3 -I 8 -L 100M 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  -m1  -L  500M  vg00" tries to create a mirror logical volume
       with 2 sides with a useable size of  500  MiB.   This  operation  would
       require  3  devices  -  two for the mirror devices and one for the disk
       log.

       "lvcreate -m1 --mirrorlog core -L 500M vg00" tries to create  a  mirror
       logical  volume  with  2  sides  with  a useable size of 500 MiB.  This
       operation would require 2 devices - the log is "in-memory".

       "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 original  logical  volume
       contains a file system, you can mount the snapshot logical volume on an
       arbitrary directory in order to access the contents of  the  filesystem
       to run a backup while the original filesystem continues to get updated.

       "lvcreate --virtualsize 1T --size 100M --snapshot --name sparse vg1"
       creates  a  sparse  device named /dev/vg1/sparse of size 1TB with space
       for just under 100MB of actual data on it.

       "lvcreate -L 64M -n lvol1 vg00 /dev/sda:0-7 /dev/sdb:0-7"
       creates a linear logical volume  "vg00/lvol1"  using  physical  extents
       /dev/sda:0-7 and /dev/sdb:0-7 for allocation of extents.

SEE ALSO

       lvm(8), vgcreate(8), lvremove(8), lvrename(8) lvextend(8), lvreduce(8),
       lvdisplay(8), lvscan(8)