lvmdevices(8) — Linux manual page


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

NAME         top

       lvmdevices — Manage the devices file

SYNOPSIS         top

       lvmdevices option_args
           [ option_args ]

           --adddev PV
           --addpvid String
           --commandprofile String
           --config String
           --deldev PV
           --delpvid String
           --deviceidtype String
           --devices PV
           --devicesfile String
           --driverloaded y|n
           --journal String
           --lockopt String
           --profile String

DESCRIPTION         top

       The LVM devices file lists devices that lvm can use.  The default
       file is /etc/lvm/devices/system.devices, and the lvmdevices(8)
       command is used to add or remove device entries.  If the file
       does not exist, or if lvm.conf includes use_devicesfile=0, then
       lvm will not use a devices file.

       To use a device with lvm, add it to the devices file with the
       command lvmdevices --adddev, and to prevent lvm from seeing or
       using a device, remove it from the devices file with lvmdevices
       --deldev.  The vgimportdevices(8) command adds all PVs from a VG
       to the devices file, and updates the VG metadata to include
       device IDs of the PVs.

       Commands that add new devices to the devices file necessarily
       look outside the existing devices file to find the devices being
       added.  pvcreate, vgcreate, and vgextend also look outside the
       devices file to create new PVs and add those PVs to the devices

       LVM records devices in the devices file using hardware-specific
       IDs, such as the WWID, and attempts to use subsystem-specific IDs
       for virtual device types (which also aim to be as unique and
       stable as possible.) These device IDs are also written in the VG
       metadata.  When no hardware or virtual ID is available, lvm falls
       back using the unstable device name as the device ID.  When
       devnames are used as IDs, lvm performs extra scanning to find
       devices if their devname changes, e.g. after reboot.

       When proper device IDs are used, an lvm command will not look at
       devices outside the devices file, but when devnames are used as a
       fallback, lvm will scan devices outside the devices file to
       locate PVs on renamed devices.  A config setting
       search_for_devnames can be used to control the scanning for
       renamed devname entries.

       Related to the devices file, the command option --devices
       <devnames> allows a list of devices to be specified for the
       command to use, overriding the devices file.  The listed devices
       act as a sort of devices file in terms of limiting which devices
       lvm will see and use.  Devices that are not listed will appear to
       be missing to the lvm command.

       Multiple devices files can be kept in /etc/lvm/devices, which
       allows lvm to be used with different sets of devices.  For
       example, system devices do not need to be exposed to a specific
       application, and the application can use lvm on its own devices
       that are not exposed to the system.  The option --devicesfile
       <filename> is used to select the devices file to use with the
       command.  Without the option set, the default system devices file
       is used.

       Setting --devicesfile "" causes lvm to not use a devices file.

       With no devices file, lvm will use any device on the system, and
       applies the filter to limit the full set of system devices.  With
       a devices file, the regex filter is not used, and the filter
       settings in lvm.conf or the command line are ignored.  The
       vgimportdevices command is one exception which does apply the
       regex filter when looking for a VG to import.

       If a devices file exists, lvm will use it, even if it's empty.
       An empty devices file means lvm will see no devices.

       If the system devices file does not yet exist, the pvcreate or
       vgcreate commands will create it if they see no existing VGs on
       the system.  lvmdevices --addev and vgimportdevices will always
       create a new devices file if it does not yet exist.

       It is recommended to use lvm commands to make changes to the
       devices file to ensure proper updates.

       The device ID and device ID type are included in the VG metadata
       and can be reported with pvs -o deviceid,deviceidtype.  (Note
       that the lvmdevices command does not update VG metadata, but
       subsequent lvm commands modifying the metadata will include the
       device ID.)

       Possible device ID types are:

       • sys_wwid uses the wwid reported by the wwid sysfs file. This is
         the first choice.

       • wwid_naa uses the naa wwid decoded from the vpd_pg83 sysfs

       • wwid_eui uses the eui wwid decoded from the vpd_pg83 sysfs

       • wwid_t10 uses the t10 wwid decoded from the vpd_pg83 sysfs

       • sys_serial uses the serial number reported by the serial sysfs
         file or the vpd_pg80 file. A serial number is used if no wwid
         is available.

       • mpath_uuid is used for dm multipath devices, reported by sysfs.

       • crypt_uuid is used for dm crypt devices, reported by sysfs.

       • md_uuid is used for md devices, reported by sysfs.

       • lvmlv_uuid is used if a PV is placed on top of an lvm LV,
         reported by sysfs.

       • loop_file is used for loop devices, the backing file name
         repored by sysfs.

       • devname the device name is used if no other type applies.

       The default choice for device ID type can be overridden using
       lvmdevices --addev --deviceidtype <type>.  If the specified type
       is available for the device it will be used, otherwise the device
       will be added using the type that would otherwise be chosen.

       LVM commands run by dmeventd will use the devices file
       /etc/lvm/devices/dmeventd.devices if it exists, otherwise
       system.devices is used.  VGs that require the dmeventd service
       should be included in system.devices, even if they are included
       in dmeventd.devices.

   Device ID refresh
       A machine identifier is saved in the devices file, and is used to
       detect when the devices file has been created by a different
       machine. If the devices file was created by a different machine,
       it indicates that PVs may have been copied or restored onto new
       devices on a new machine. In this case, lvm will search for the
       PVs listed in system.devices on new devices.  If found, the
       device IDs will be updated in system.devices for the existing
       PVIDs (assuming the original device IDs are also no longer

       The machine identifier used in system.devices will be either the
       DMI product_uuid from /sys/devices/virtual/dmi/id/product_uuid,
       or the hostname from uname(2). See lvm.conf
       device_ids_refresh_checks to configure this.

USAGE         top

       Print devices in the devices file.

           [ COMMON_OPTIONS ]


       Check the devices file and report incorrect values.

       lvmdevices --check
           [ COMMON_OPTIONS ]


       Update the devices file to fix incorrect values.

       lvmdevices --update
           [ COMMON_OPTIONS ]


       Add a device to the devices file.

       lvmdevices --adddev PV
           [    --deviceidtype String ]
           [ COMMON_OPTIONS ]


       Remove a device from the devices file.

       lvmdevices --deldev PV
           [ COMMON_OPTIONS ]


       Find the device with the given PVID and add it to the devices

       lvmdevices --addpvid String
           [    --deviceidtype String ]
           [ COMMON_OPTIONS ]


       Remove the devices file entry for the given PVID.

       lvmdevices --delpvid 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 ]

OPTIONS         top

       --adddev PV
              Add a device to the devices file.

       --addpvid String
              Find a device with the PVID and add the device to the
              devices file.

              Checks the content of the devices file.  Reports incorrect
              device names or PVIDs for entries.

       --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.

       -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

       --deldev PV
              Remove a device from the devices file.

       --delpvid String
              Remove a device with the PVID from the devices file.

       --deviceidtype String
              The type of device ID to use for the device.  If the
              specified type is available for the device, then it will
              override the default type that lvm would use.

       --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.

              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.

       --lockopt String
              Used to pass options for special cases to lvmlockd.  See
              lvmlockd(8) for more information.

              Display long help text.

              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.

              Disable locking.

       --profile String
              An alias for --commandprofile or --metadataprofile,
              depending on the command.

       -q|--quiet ...
              Suppress output and log messages. Overrides --debug and
              --verbose.  Repeat once to also suppress any prompts with
              answer 'no'.

              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.

              Update the content of the devices file.

       -v|--verbose ...
              Set verbose level. Repeat from 1 to 4 times to increase
              the detail of messages sent to stdout and stderr.

              Display version information.

              Do not prompt for confirmation interactively but always
              assume the answer yes. Use with extreme caution.  (For
              automatic no, see -qq.)

VARIABLES         top

       String See the option description for information about the
              string content.

              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


       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.

SEE ALSO         top

       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)

COLOPHON         top

       This page is part of the lvm2 (Logical Volume Manager 2) project.
       Information about the project can be found at 
       ⟨⟩.  If you have a bug report for
       this manual page, see ⟨⟩.
       This page was obtained from the project's upstream Git repository
       ⟨git://⟩ on 2023-12-22.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2023-12-06.)  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

Red Hat, Inc.     LVM TOOLS 2.03.24(2)-git (2023-11-21)    LVMDEVICES(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)