# lvmdevices

## NAME



           lvmdevices — Manage the devices file
    


## SYNOPSIS



           **lvmdevices** _option_args_
               [ _option_args_ ]
    
               **--adddev** _PV_
               **--addpvid** _String_
               **--check**
               **--commandprofile** _String_
               **--config** _String_
            **-d** |**--debug**
               **--deldev** _PV_
               **--delpvid** _String_
               **--deviceidtype** _String_
               **--devices** _PV_
               **--devicesfile** _String_
               **--driverloaded y** |**n**
            **-h** |**--help**
               **--journal** _String_
               **--lockopt** _String_
               **--longhelp**
               **--nohints**
               **--nolocking**
               **--profile** _String_
            **-q** |**--quiet**
            **-t** |**--test**
               **--update**
            **-v** |**--verbose**
               **--version**
            **-y** |**--yes**
    


## DESCRIPTION



           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 file.
    
           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 file.
    
           • **wwid_eui** uses the eui wwid decoded from the vpd_pg83 sysfs file.
    
           • **wwid_t10** uses the t10 wwid decoded from the vpd_pg83 sysfs file.
    
           • **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
             reported 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 found.)
    
           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(5)
           **device_ids_refresh_checks to** configure this.
    


## USAGE



           Print devices in the devices file.
    
           **lvmdevices**
               [ 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
           file.
    
           **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



    
           **--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.
    
           **--check**
                  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
                  configured).
    
           **--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.
    
           **-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.
    
           **--lockopt** _String_
                  Used to pass options for special cases  to  lvmlockd.   See
                  lvmlockd(8) for more information.
    
           **--longhelp**
                  Display long help text.
    
           **--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.
    
           **--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'.
    
           **-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.
    
           **--update**
                  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.
    
           **--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.)
    


## VARIABLES



           _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.)
    


## ENVIRONMENT VARIABLES



           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.
    


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