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pvcreate(8) - phpMan
PVCREATE(8) System Manager's Manual PVCREATE(8)
NAME
pvcreate — initialize a disk or partition for use by LVM
SYNOPSIS
pvcreate [--commandprofile ProfileName] [-d|--debug] [-h|--help] [-t|--test] [-v|--ver‐
bose] [--version] [-f[f]|--force [--force]] [-y|--yes] [--labelsector] [--bootloaderarea‐
size size] [-M|--metadatatype type] [--[pv]metadatacopies NumberOfCopies] [--metadatasize
size] [--metadataignore {y|n}] [--dataalignment alignment] [--dataalignmentoffset align‐
ment_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 ran‐
dom 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 effi‐
cient 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 writ‐
ten 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 Vol‐
umes 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 requir‐
ing 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 boot‐
loader 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 con‐
sequently sector 63 is aligned on a 4KiB boundary) manually account for this when initial‐
izing 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), los‐
etup(8), mdadm(8), vgcfgrestore(8), vgconvert(8)
Sistina Software UK LVM TOOLS 2.02.111(2) (2014-09-01) PVCREATE(8)
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