pvcreate(8) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | USAGE | OPTIONS | VARIABLES | ENVIRONMENT VARIABLES | EXAMPLES | SEE ALSO | COLOPHON

PVCREATE(8)              System Manager's Manual             PVCREATE(8)

NAME         top

       pvcreate - Initialize physical volume(s) for use by LVM

SYNOPSIS         top

       pvcreate position_args
           [ option_args ]

DESCRIPTION         top

       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
       overriden 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 --dataaligmentoffset
       option.  The pe_start alignment is calculated as described above,
       and then the value specified with --dataaligmentoffset is added
       to produce the final pe_start value.

USAGE         top

       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 ]
           [    --driverloaded y|n ]
           [    --lockopt String ]
           [    --longhelp ]
           [    --nolocking ]
           [    --profile String ]
           [    --version ]

OPTIONS         top

       --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
              settings.  The String arg uses the same format as
              lvm.conf, 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).

       --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.

       --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.

       --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.  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.

VARIABLES         top

       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: bBsSkKmMgGtTpPeE.  b|B is bytes, s|S is sectors of
              512 bytes, k|K is kilobytes, m|M is megabytes, g|G is
              gigabytes, t|T is terabytes, p|P is petabytes, e|E is
              exabytes.  (This should not be confused with the output
              control --units, where capital letters mean multiple of
              1000.)

ENVIRONMENT VARIABLES         top

       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.

EXAMPLES         top

       Initialize a partition and a full device.
       pvcreate /dev/sdc4 /dev/sde

       If a device 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

SEE ALSO         top

       lvm(8) lvm.conf(5) lvmconfig(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) 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) lvm2-activation-generator(8)
       blkdeactivate(8) lvmdump(8)

       dmeventd(8) lvmpolld(8) lvmlockd(8) lvmlockctl(8) cmirrord(8)
       lvmdbusd(8)

       lvmsystemid(7) lvmreport(7) lvmraid(7) lvmthin(7) lvmcache(7)

COLOPHON         top

       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 tarball
       https://github.com/lvmteam/lvm2/archive/v2_03_10.tar.gz fetched
       from ⟨https://github.com/lvmteam/lvm2/releases⟩ on 2020-12-18.
       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 2.03.10(2) (2020-08-09)        PVCREATE(8)

Pages that refer to this page: lvchange(8)lvconvert(8)lvcreate(8)lvdisplay(8)lvextend(8)lvm(8)lvmconfig(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)vgmerge(8)vgmknodes(8)vgreduce(8)vgremove(8)vgrename(8)vgs(8)vgscan(8)vgsplit(8)