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NAME | SYNOPSIS | DESCRIPTION | USAGE | OPTIONS | VARIABLES | ENVIRONMENT VARIABLES | EXAMPLES | SEE ALSO | COLOPHON |
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PVCREATE(8) System Manager's Manual PVCREATE(8)
pvcreate — Initialize physical volume(s) for use by LVM
pvcreate position_args
[ option_args ]
pvcreate initializes a Physical Volume (PV) on a device so the
device is recognized as belonging to LVM. This allows the PV to
be used in a Volume Group (VG). An LVM disk label is written to
the device, and LVM metadata areas are initialized. A PV can be
placed on a whole device or partition.
Use vgcreate(8) to create a new VG on the PV, or vgextend(8) to
add the PV to an existing VG. Use pvremove(8) to remove the LVM
disk label from the device.
The force option will create a PV without confirmation.
Repeating the force option (-ff) will forcibly create a PV,
overriding checks that normally prevent it, e.g. if the PV is
already in a VG.
Metadata location, size, and alignment
The LVM disk label begins 512 bytes from the start of the device,
and is 512 bytes in size.
The LVM metadata area begins at an offset (from the start of the
device) equal to the page size of the machine creating the PV
(often 4 KiB.) The metadata area contains a 512 byte header and a
multi-KiB circular buffer that holds text copies of the VG
metadata.
With default settings, the first physical extent (PE), which
contains LV data, is 1 MiB from the start of the device. This
location is controlled by default_data_alignment in lvm.conf,
which is set to 1 (MiB) by default. The pe_start will be a
multiple of this many MiB. This location can be checked with:
pvs -o pe_start PV
The size of the LVM metadata area is the space between the the
start of the metadata area and the first PE. When metadata
begins at 4 KiB and the first PE is at 1024 KiB, the metadata
area size is 1020 KiB. This can be checked with:
pvs -o mda_size PV
The mda_size cannot be increased after pvcreate, so if larger
metadata is needed, it must be set during pvcreate. Two copies
of the VG metadata must always fit within the metadata area, so
the maximum VG metadata size is around half the mda_size. This
can be checked with:
vgs -o mda_free VG
A larger metadata area can be set with --metadatasize. The
resulting mda_size may be larger than specified due to
default_data_alignment placing pe_start on a MiB boundary, and
the fact that the metadata area extends to the first PE. With
metadata starting at 4 KiB and default_data_alignment 1 (MiB),
setting --metadatasize 2048k results in pe_start of 3 MiB and
mda_size of 3068 KiB. Alternatively, --metadatasize 2044k
results in pe_start at 2 MiB and mda_size of 2044 KiB.
The alignment of pe_start described above may be automatically
overridden based on md device properties or device i/o properties
reported in sysfs. These automatic adjustments can be
enabled/disabled using lvm.conf settings md_chunk_alignment and
data_alignment_offset_detection.
To use a different pe_start alignment, use the --dataalignment
option. The --metadatasize option would also typically be used
in this case because the metadata area size also determines the
location of pe_start. When using these two options together,
pe_start is calculated as: metadata area start (page size), plus
the specified --metadatasize, rounded up to the next multiple of
--dataalignment. With metadata starting at 4 KiB, --metadatasize
2048k, and --dataalignment 128k, pe_start is 2176 KiB and
mda_size is 2172 KiB. The pe_start of 2176 KiB is the nearest
even multiple of 128 KiB that provides at least 2048 KiB of
metadata space. Always check the resulting alignment and
metadata size when using these options.
To shift an aligned pe_start value, use the --dataalignmentoffset
option. The pe_start alignment is calculated as described above,
and then the value specified with --dataalignmentoffset is added
to produce the final pe_start value.
pvcreate PV ...
[ -f|--force ]
[ -M|--metadatatype lvm2 ]
[ -u|--uuid String ]
[ -Z|--zero y|n ]
[ --dataalignment Size[k|UNIT] ]
[ --dataalignmentoffset Size[k|UNIT] ]
[ --bootloaderareasize Size[m|UNIT] ]
[ --labelsector Number ]
[ --[pv]metadatacopies 0|1|2 ]
[ --metadatasize Size[m|UNIT] ]
[ --metadataignore y|n ]
[ --norestorefile ]
[ --setphysicalvolumesize Size[m|UNIT] ]
[ --reportformat basic|json ]
[ --restorefile String ]
[ COMMON_OPTIONS ]
Common options for lvm:
[ -d|--debug ]
[ -h|--help ]
[ -q|--quiet ]
[ -t|--test ]
[ -v|--verbose ]
[ -y|--yes ]
[ --commandprofile String ]
[ --config String ]
[ --devices PV ]
[ --devicesfile String ]
[ --driverloaded y|n ]
[ --journal String ]
[ --lockopt String ]
[ --longhelp ]
[ --nohints ]
[ --nolocking ]
[ --profile String ]
[ --version ]
--bootloaderareasize Size[m|UNIT]
Reserve space for the bootloader between the LVM metadata
area and the first PE. The bootloader area is reserved
for bootloaders to embed their own data or metadata; LVM
will not use it. The bootloader area begins where the
first PE would otherwise be located. The first PE is
moved out by the size of the bootloader area, and then
moved out further if necessary to match the data
alignment. The start of the bootloader area is always
aligned, see also --dataalignment and
--dataalignmentoffset. The bootloader area may be larger
than requested due to the alignment, but it's never less
than the requested size. To see the bootloader area start
and size of an existing PV use pvs -o
+pv_ba_start,pv_ba_size.
--commandprofile String
The command profile to use for command configuration. See
lvm.conf(5) for more information about profiles.
--config String
Config settings for the command. These override
lvm.conf(5) settings. The String arg uses the same format
as lvm.conf(5), or may use section/field syntax. See
lvm.conf(5) for more information about config.
--dataalignment Size[k|UNIT]
Align the start of a PV data area with a multiple of this
number. To see the location of the first Physical Extent
(PE) of an existing PV, use pvs -o +pe_start. In addition,
it may be shifted by an alignment offset, see
--dataalignmentoffset. Also specify an appropriate PE
size when creating a VG.
--dataalignmentoffset Size[k|UNIT]
Shift the start of the PV data area by this additional
offset.
-d|--debug ...
Set debug level. Repeat from 1 to 6 times to increase the
detail of messages sent to the log file and/or syslog (if
configured).
--devices PV
Devices that the command can use. This option can be
repeated or accepts a comma separated list of devices.
This overrides the devices file.
--devicesfile String
A file listing devices that LVM should use. The file must
exist in /etc/lvm/devices/ and is managed with the
lvmdevices(8) command. This overrides the lvm.conf(5)
devices/devicesfile and devices/use_devicesfile settings.
--driverloaded y|n
If set to no, the command will not attempt to use device-
mapper. For testing and debugging.
-f|--force ...
Override various checks, confirmations and protections.
Use with extreme caution.
-h|--help
Display help text.
--journal String
Record information in the systemd journal. This
information is in addition to information enabled by the
lvm.conf log/journal setting. command: record information
about the command. output: record the default command
output. debug: record full command debugging.
--labelsector Number
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.
--lockopt String
Used to pass options for special cases to lvmlockd. See
lvmlockd(8) for more information.
--longhelp
Display long help text.
--metadataignore y|n
Specifies the metadataignore property of a PV. If yes,
metadata areas on the PV are ignored, and lvm will not
store metadata in the metadata areas of the PV. If no,
lvm will store metadata on the PV.
--metadatasize Size[m|UNIT]
The approximate amount of space used for each VG metadata
area. The size may be rounded.
-M|--metadatatype lvm2
Specifies the type of on-disk metadata to use. lvm2 (or
just 2) is the current, standard format. lvm1 (or just 1)
is no longer used.
--nohints
Do not use the hints file to locate devices for PVs. A
command may read more devices to find PVs when hints are
not used. The command will still perform standard hint
file invalidation where appropriate.
--nolocking
Disable locking.
--norestorefile
In conjunction with --uuid, this allows a uuid to be
specified without also requiring that a backup of the
metadata be provided.
--profile String
An alias for --commandprofile or --metadataprofile,
depending on the command.
--[pv]metadatacopies 0|1|2
The number of metadata areas to set aside on a PV for
storing VG metadata. When 2, one copy of the VG metadata
is stored at the front of the PV and a second copy is
stored at the end. When 1, one copy of the VG metadata is
stored at the front of the PV. When 0, no copies of the
VG metadata are stored on the given PV. This may be
useful in VGs containing many PVs (this places limitations
on the ability to use vgsplit later.)
-q|--quiet ...
Suppress output and log messages. Overrides --debug and
--verbose. Repeat once to also suppress any prompts with
answer 'no'.
--reportformat basic|json
Overrides current output format for reports which is
defined globally by the report/output_format setting in
lvm.conf(5). basic is the original format with columns
and rows. If there is more than one report per command,
each report is prefixed with the report name for
identification. json produces report output in JSON
format. See lvmreport(7) for more information.
--restorefile String
In conjunction with --uuid, this reads the file (produced
by vgcfgbackup), extracts the location and size of the
data on the PV, and ensures that the metadata produced by
the program is consistent with the contents of the file,
i.e. the physical extents will be in the same place and
not be overwritten by new metadata. This provides a
mechanism to upgrade the metadata format or to add/remove
metadata areas. Use with care.
--setphysicalvolumesize Size[m|UNIT]
Overrides the automatically detected size of the PV. Use
with care, or prior to reducing the physical size of the
device.
-t|--test
Run in test mode. Commands will not update metadata. This
is implemented by disabling all metadata writing but
nevertheless returning success to the calling function.
This may lead to unusual error messages in multi-stage
operations if a tool relies on reading back metadata it
believes has changed but hasn't.
-u|--uuid String
Specify a UUID for the device. Without this option, a
random UUID is generated. This option is needed 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. All PVs
must have unique UUIDs, and LVM will prevent certain
operations if multiple devices are seen with the same
UUID. See vgimportclone(8) for more information.
-v|--verbose ...
Set verbose level. Repeat from 1 to 4 times to increase
the detail of messages sent to stdout and stderr.
--version
Display version information.
-y|--yes
Do not prompt for confirmation interactively but always
assume the answer yes. Use with extreme caution. (For
automatic no, see -qq.)
-Z|--zero y|n
Controls if the first 4 sectors (2048 bytes) of the device
are wiped. The default is to wipe these sectors unless
either or both of --restorefile or --uuid are specified.
PV Physical Volume name, a device path under /dev. For
commands managing physical extents, a PV positional arg
generally accepts a suffix indicating a range (or multiple
ranges) of physical extents (PEs). When the first PE is
omitted, it defaults to the start of the device, and when
the last PE is omitted it defaults to end. Start and end
range (inclusive): PV[:PE-PE]... Start and length range
(counting from 0): PV[:PE+PE]...
String See the option description for information about the
string content.
Size[UNIT]
Size is an input number that accepts an optional unit.
Input units are always treated as base two values,
regardless of capitalization, e.g. 'k' and 'K' both refer
to 1024. The default input unit is specified by letter,
followed by |UNIT. UNIT represents other possible input
units: b|B is bytes, s|S is sectors of 512 bytes, k|K is
KiB, m|M is MiB, g|G is GiB, t|T is TiB, p|P is PiB, e|E
is EiB. (This should not be confused with the output
control --units, where capital letters mean multiple of
1000.)
See lvm(8) for information about environment variables used by
lvm. For example, LVM_VG_NAME can generally be substituted for a
required VG parameter.
Initialize a partition and a full device.
pvcreate /dev/sdc4 /dev/sde
If a device is a 4 KiB sector drive that compensates for windows
partitioning (sector 7 is the lowest aligned logical block, the
4 KiB sectors start at LBA -1, and consequently sector 63 is
aligned on a 4 KiB boundary) manually account for this when
initializing for use by LVM.
pvcreate --dataalignmentoffset 7s /dev/sdb
lvm(8), lvm.conf(5), lvmconfig(8), lvmdevices(8),
pvchange(8), pvck(8), pvcreate(8), pvdisplay(8), pvmove(8),
pvremove(8), pvresize(8), pvs(8), pvscan(8),
vgcfgbackup(8), vgcfgrestore(8), vgchange(8), vgck(8),
vgcreate(8), vgconvert(8), vgdisplay(8), vgexport(8),
vgextend(8), vgimport(8), vgimportclone(8), vgimportdevices(8),
vgmerge(8), vgmknodes(8), vgreduce(8), vgremove(8), vgrename(8),
vgs(8), vgscan(8), vgsplit(8),
lvcreate(8), lvchange(8), lvconvert(8), lvdisplay(8),
lvextend(8), lvreduce(8), lvremove(8), lvrename(8), lvresize(8),
lvs(8), lvscan(8),
lvm-fullreport(8), lvm-lvpoll(8), blkdeactivate(8), lvmdump(8),
dmeventd(8), lvmpolld(8), lvmlockd(8), lvmlockctl(8),
cmirrord(8), lvmdbusd(8), fsadm(8),
lvmsystemid(7), lvmreport(7), lvmcache(7), lvmraid(7),
lvmthin(7), lvmvdo(7), lvmautoactivation(7)
This page is part of the lvm2 (Logical Volume Manager 2) project.
Information about the project can be found at
⟨http://www.sourceware.org/lvm2/⟩. If you have a bug report for
this manual page, see ⟨https://github.com/lvmteam/lvm2/issues⟩.
This page was obtained from the project's upstream Git repository
⟨git://sourceware.org/git/lvm2.git⟩ on 2024-06-14. (At that
time, the date of the most recent commit that was found in the
repository was 2024-06-11.) If you discover any rendering
problems in this HTML version of the page, or you believe there
is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
man-pages@man7.org
Red Hat, Inc. LVM TOOLS 2.03.25(2)-git (2024-05-16) PVCREATE(8)
Pages that refer to this page: lvchange(8), lvconvert(8), lvcreate(8), lvdisplay(8), lvextend(8), lvm(8), lvmconfig(8), lvmdevices(8), lvmdiskscan(8), lvm-fullreport(8), lvm-lvpoll(8), lvreduce(8), lvremove(8), lvrename(8), lvresize(8), lvs(8), lvscan(8), pvchange(8), pvck(8), pvcreate(8), pvdisplay(8), pvmove(8), pvremove(8), pvresize(8), pvs(8), pvscan(8), vgcfgbackup(8), vgcfgrestore(8), vgchange(8), vgck(8), vgconvert(8), vgcreate(8), vgdisplay(8), vgexport(8), vgextend(8), vgimport(8), vgimportclone(8), vgimportdevices(8), vgmerge(8), vgmknodes(8), vgreduce(8), vgremove(8), vgrename(8), vgs(8), vgscan(8), vgsplit(8)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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