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NAME | SYNOPSIS | DESCRIPTION | USAGE | OPTIONS | VARIABLES | ENVIRONMENT VARIABLES | SEE ALSO | COLOPHON |
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LVMDEVICES(8) System Manager's Manual LVMDEVICES(8)
lvmdevices — Manage the devices file
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
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
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
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
device_ids_refresh_checks to configure this.
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 ]
--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.)
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.
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
[email protected]
Red Hat, Inc. LVM TOOLS 2.03.25(2)-git (2024-05-16) 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)
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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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