Ubuntu Manpage: pvcreate — initialize a disk or partition for use by LVM

name
synopsis
description
options
new metadata options
examples
see also

Provided by: lvm2_2.02.133-1ubuntu10_amd64

NAME

       pvcreate — initialize a disk or partition for use by LVM

SYNOPSIS

       pvcreate  [--commandprofile  ProfileName] [-d|--debug] [-h|--help] [-t|--test] [-v|--verbose] [--version]
       [-f[f]|--force [--force]] [-y|--yes] [--labelsector] [--bootloaderareasize size] [-M|--metadatatype type]
       [--[pv]metadatacopies  NumberOfCopies]  [--metadatasize  size]  [--metadataignore {y|n}] [--dataalignment
       alignment]    [--dataalignmentoffset    alignment_offset]    [--restorefile    file]    [--norestorefile]
       [--setphysicalvolumesize size] [-u|--uuid uuid] [-Z|--zero {y|n}] PhysicalVolume [PhysicalVolume...]

DESCRIPTION

       pvcreate   initializes  PhysicalVolume  for  later  use  by  the  Logical  Volume  Manager  (LVM).   Each
       PhysicalVolume can be a disk partition, whole  disk,  meta  device,  or  loopback  file.   For  DOS  disk
       partitions, the partition id should be set to 0x8e using fdisk(8), cfdisk(8), or a equivalent.  For whole
       disk devices only the partition table must be erased, which will effectively destroy  all  data  on  that
       disk.  This can be done by zeroing the first sector with:

       dd if=/dev/zero of=PhysicalVolume bs=512 count=1

       Continue  with  vgcreate(8)  to  create  a  new  volume  group  on  PhysicalVolume, or vgextend(8) to add
       PhysicalVolume to an existing volume group.

OPTIONS

       See lvm(8) for common options.

       -f, --force
              Force the creation without any confirmation.  You  can  not  recreate  (reinitialize)  a  physical
              volume  belonging  to  an  existing volume group.  In an emergency you can override this behaviour
              with -ff.

       -u, --uuid uuid
              Specify the uuid for the device.  Without this option, pvcreate(8) generates a random  uuid.   All
              of  your  physical volumes must have unique uuids.  You need to use this option before restoring a
              backup of LVM metadata onto  a  replacement  device  -  see  vgcfgrestore(8).   As  such,  use  of
              --restorefile is compulsory unless the --norestorefile is used.

       -y, --yes
              Answer yes to all questions.

       -Z, --zero {y|n}
              Whether  or not the first 4 sectors (2048 bytes) of the device should be wiped.  If this option is
              not given, the default is to wipe these sectors unless either or  both  of  the  --restorefile  or
              --uuid options were specified.

NEW METADATA OPTIONS

LVM2 introduces a new format for storing metadata on disk. This new format is more efficient and
resilient than the format the original version of LVM used and offers the advanced user greater
flexibility and control.

The new format may be selected on the command line with -M2 or by setting format = "lvm2" in the global
section of lvm.conf(5). Each physical volume in the same volume group must use the same format, but
different volume groups on a machine may use different formats simultaneously: the tools can handle both
formats. Additional formats can be added as shared libraries.

Additional tools for manipulating the locations and sizes of metadata areas will be written in due
course. Use the verbose/debug options on the tools to see where the metadata areas are placed.

--metadatasize size
The approximate amount of space to be set aside for each metadata area. (The size you specify may
get rounded.)

--dataalignment alignment
Align the start of the data to a multiple of this number. You should also specify an appropriate
PhysicalExtentSize when creating the Volume Group with vgcreate.

To see the location of the first Physical Extent of an existing Physical Volume use pvs -o
+pe_start . It will be a multiple of the requested alignment. In addition it may be shifted by
alignment_offset from data_alignment_offset_detection (if enabled in lvm.conf(5)) or
--dataalignmentoffset.

--dataalignmentoffset alignment_offset
Shift the start of the data area by this additional alignment_offset.

--[pv]metadatacopies NumberOfCopies
The number of metadata areas to set aside on each PV. Currently this can be 0, 1 or 2. If set to
2, two copies of the volume group metadata are held on the PV, one at the front of the PV and one
at the end. If set to 1 (the default), one copy is kept at the front of the PV (starting in the
5th sector). If set to 0, no copies are kept on this PV - you might wish to use this with VGs
containing large numbers of PVs. But if you do this and then later use vgsplit(8) you must ensure
that each VG is still going to have a suitable number of copies of the metadata after the split!

--metadataignore {y|n}
Ignore or un-ignore metadata areas on this physical volume. The default is "n". This setting can
be changed with pvchange. If metadata areas on a physical volume are ignored, LVM will not store
metadata in the metadata areas present on this Physical Volume. Metadata areas cannot be created
or extended after Logical Volumes have been allocated on the device. If you do not want to store
metadata on this device, it is still wise always to allocate a metadata area in case you need it
in the future and to use this option to instruct LVM2 to ignore it.

--restorefile file
In conjunction with --uuid, this extracts the location and size of the data on the PV from the
file (produced by vgcfgbackup) and ensures that the metadata that the program produces is
consistent with the contents of the file i.e. the physical extents will be in the same place and
not get overwritten by new metadata. This provides a mechanism to upgrade the metadata format or
to add/remove metadata areas. Use with care. See also vgconvert(8).

--norestorefile
In conjunction with --uuid, this allows a uuid to be specified without also requiring that a
backup of the metadata be provided.

--labelsector sector
By default the PV is labelled with an LVM2 identifier in its second sector (sector 1). This lets
you use a different sector near the start of the disk (between 0 and 3 inclusive - see
LABEL_SCAN_SECTORS in the source). Use with care.

--bootloaderareasize size
Create a separate bootloader area of specified size besides PV's data area. The bootloader area is
an area of reserved space on the PV from which LVM2 will not allocate any extents and it's kept
untouched. This is primarily aimed for use with bootloaders to embed their own data or metadata.
The start of the bootloader area is always aligned, see also --dataalignment and
--dataalignmentoffset. The bootloader area size may eventually end up increased due to the
alignment, but it's never less than the size that is requested. To see the bootloader area start
and size of an existing Physical Volume use pvs -o +pv_ba_start,pv_ba_size.

--setphysicalvolumesize size
Overrides the automatically-detected size of the PV. Use with care.

Examples

       Initialize partition #4 on the third SCSI disk and the entire fifth SCSI disk for later use by LVM:

       pvcreate /dev/sdc4 /dev/sde

       If  the  2nd  SCSI disk is a 4KiB sector drive that compensates for windows partitioning (sector 7 is the
       lowest aligned logical block, the 4KiB sectors start at LBA -1, and consequently sector 63 is aligned  on
       a 4KiB boundary) manually account for this when initializing for use by LVM:

       pvcreate --dataalignmentoffset 7s /dev/sdb