NAME
pvcreate - initialize a disk or partition for use by LVM
SYNOPSIS
pvcreate [-d|--debug] [-h|--help] [-t|--test] [-v|--verbose]
[--version] [-f[f]|--force [--force]] [-y|--yes] [--labelsector]
[-M|--metadatatype type] [--[pv]metadatacopies #copies] [--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
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. 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) or --dataalignmentoffset.
--dataalignmentoffset alignment_offset
Shift the start of the data area by this additional
alignment_offset.
--[pv]metadatacopies copies
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 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
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.
--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 4KB sector drive that compensates for windows
partitioning (sector 7 is the lowest aligned logical block, the 4KB
sectors start at LBA -1, and consequently sector 63 is aligned on a 4KB
boundary) manually account for this when initializing for use by LVM:
pvcreate --dataalignmentoffset 7s /dev/sdb
SEE ALSO
lvm.conf(5), lvm(8), vgcreate(8), vgextend(8), lvcreate(8), cfdisk(8),
fdisk(8), losetup(8), mdadm(8), vgcfgrestore(8), vgconvert(8)