dmsetup

SYNOPSIS

? ? ? dmsetup clear device_name

? ? ? dmsetup create device_name [-u|--uuid uuid]

? ? ? ? ? ? ? ? [--addnodeoncreate|--addnodeonresume] [-n|--notable|--table

? ? ? ? ? ? ? ? table|table_file] [--readahead [+]sectors|auto|none]

? ? ? dmsetup create --concise [concise_device_specification]

? ? ? dmsetup deps [-o options] [device_name...]

? ? ? dmsetup help [-c|-C|--columns]

? ? ? dmsetup info [device_name...]

? ? ? dmsetup info -c|-C|--columns [--count count] [--interval seconds]

? ? ? ? ? ? ? ? [--nameprefixes] [--noheadings] [-o fields] [-O|--sort

? ? ? ? ? ? ? ? sort_fields] [--separator separator] [device_name]

? ? ? dmsetup load device_name [--table table|table_file]

? ? ? dmsetup ls [--target target_type] [--exec command] [--tree] [-o

? ? ? ? ? ? ? ? options]

? ? ? dmsetup mangle [device_name...]

? ? ? dmsetup message device_name sector message

? ? ? dmsetup mknodes [device_name...]

? ? ? dmsetup reload device_name [--table table|table_file]

? ? ? dmsetup remove [-f|--force] [--retry] [--deferred] device_name...

? ? ? dmsetup remove_all [-f|--force] [--deferred]

? ? ? dmsetup rename device_name new_name

? ? ? dmsetup rename device_name --setuuid uuid

? ? ? dmsetup resume device_name...? [--addnodeoncreate|--addnodeonresume]

? ? ? ? ? ? ? ? [--noflush] [--nolockfs] [--readahead [+]sectors|auto|none]

? ? ? dmsetup setgeometry device_name cyl head sect start

? ? ? dmsetup splitname device_name [subsystem]

? ? ? dmsetup stats command [options]

? ? ? dmsetup status [--target target_type] [--noflush] [device_name...]

? ? ? dmsetup suspend [--nolockfs] [--noflush] device_name...

? ? ? dmsetup table [--concise] [--target target_type] [--showkeys]

? ? ? ? ? ? ? ? [device_name...]

? ? ? dmsetup targets

? ? ? dmsetup udevcomplete cookie

? ? ? dmsetup udevcomplete_all [age_in_minutes]

? ? ? dmsetup udevcookie

? ? ? dmsetup udevcreatecookie

? ? ? dmsetup udevflags cookie

? ? ? dmsetup udevreleasecookie [cookie]

? ? ? dmsetup version

? ? ? dmsetup wait [--noflush] device_name [event_nr]

? ? ? dmsetup wipe_table device_name...? [-f|--force] [--noflush]

? ? ? ? ? ? ? ? [--nolockfs]

? ? ? devmap_name major minor

? ? ? devmap_name major:minor

DESCRIPTION

dmsetup? manages? logical? devices? that? use the device-mapper driver.? ? ? Devices are created by loading a table that specifies a target for each? ? ? sector (512 bytes) in the logical device.? ? ? --checks? ? ? ? ? ? ? Perform additional checks on the operations requested and report? ? ? ? ? ? ? potential problems.? Useful when? debugging? scripts.? In? some? ? ? ? ? ? ? cases these checks may slow down operations noticeably.? ? ? -c|-C|--columns? ? ? ? ? ? ? Display output in columns rather than as Field: Value lines.? ? ? --count count? ? ? ? ? ? ? Specify the number of times to repeat a report. Set this to zero? ? ? ? ? ? ? continue until interrupted.? The default interval is one second.? ? ? -f|--force? ? ? ? ? ? ? Try harder to complete operation.? ? ? -h|--help? ? ? ? ? ? ? Outputs a summary of the commands available, optionally? includ-? ? ? ? ? ? ? ing the list of report fields (synonym with help command).? ? ? --inactive? ? ? ? ? ? ? When? returning? any table information from the kernel report on? ? ? ? ? ? ? the inactive table instead of the live table.? Requires? kernel? ? ? ? ? ? ? driver version 4.16.0 or above.? ? ? --interval seconds? ? ? ? ? ? ? Specify? the? interval? in seconds between successive iterations? ? ? ? ? ? ? for repeating reports. If --interval is specified but --count is? ? ? ? ? ? ? not,? reports? will? continue? to repeat until interrupted.? The? ? ? ? ? ? ? default interval is one second.? ? ? --manglename auto|hex|none? ? ? ? ? ? ? Mangle any character not on a whitelist using mangling_mode when? ? ? ? ? ? ? processing? device-mapper? device names and UUIDs. The names and? ? ? ? ? ? ? UUIDs are mangled on input and unmangled? on? output? where? the? ? ? ? ? ? ? mangling? mode is one of: auto (only do the mangling if not man-? ? ? ? ? ? ? gled yet, do nothing if already mangled, error? on? mixed),? hex? ? ? ? ? ? ? (always? do? the mangling) and none (no mangling).? Default mode? ? ? ? ? ? ? is auto.? Character whitelist: 0-9,? A-Z,? a-z,? #+-.:=@_.? This? ? ? ? ? ? ? whitelist? is? also? supported? by? udev. Any character not on a? ? ? ? ? ? ? whitelist is replaced with its hex value (two? digits)? prefixed? ? ? ? ? ? ? by? ? \x.? ? Mangling? mode? could? be? also? set? through? ? ? ? ? ? ? DM_DEFAULT_NAME_MANGLING_MODE environment variable.? ? ? -j|--major major? ? ? ? ? ? ? Specify the major number.? ? ? -m|--minor minor? ? ? ? ? ? ? Specify the minor number.? ? ? -n|--notable? ? ? ? ? ? ? When creating a device, don't load any table.? ? ? ? ? ? ? device.? ? ? --noopencount? ? ? ? ? ? ? Tell? the? kernel not to supply the open reference count for the? ? ? ? ? ? ? device.? ? ? --noudevrules? ? ? ? ? ? ? Do not allow udev to manage nodes for devices? in? device-mapper? ? ? ? ? ? ? directory.? ? ? --noudevsync? ? ? ? ? ? ? Do not synchronise with udev when creating, renaming or removing? ? ? ? ? ? ? devices.? ? ? -o|--options options? ? ? ? ? ? ? Specify which fields to display.? ? ? --readahead [+]sectors|auto|none? ? ? ? ? ? ? Specify read ahead size in units of sectors.? The default? value? ? ? ? ? ? ? is auto which allows the kernel to choose a suitable value auto-? ? ? ? ? ? ? matically.? The + prefix lets you specify a minimum value? which? ? ? ? ? ? ? will? not? be used if it is smaller than the value chosen by the? ? ? ? ? ? ? kernel.? The value none is equivalent to specifying zero.? ? ? -r|--readonly? ? ? ? ? ? ? Set the table being loaded read-only.? ? ? -S|--select selection? ? ? ? ? ? ? Process only items that match selection criteria.? If? the? com-? ? ? ? ? ? ? mand? is? producing? report output, adding the "selected" column? ? ? ? ? ? ? (-o selected) displays all rows and shows 1 if the? row? matches? ? ? ? ? ? ? the? selection? and? 0? otherwise.? The? selection? criteria are? ? ? ? ? ? ? defined by specifying column names and their valid values? while? ? ? ? ? ? ? making? use? of? supported comparison operators. As a quick help? ? ? ? ? ? ? and to see full list of column names that can be used in? selec-? ? ? ? ? ? ? tion? and? the? set? of supported selection operators, check the? ? ? ? ? ? ? output of dmsetup info -c -S help command.? ? ? --table table? ? ? ? ? ? ? Specify a one-line table directly? on? the? command? line.? See? ? ? ? ? ? ? below for more information on the table format.? ? ? --udevcookie cookie? ? ? ? ? ? ? Use? cookie? for udev synchronisation.? Note: Same cookie should? ? ? ? ? ? ? be used for same type of operations i.e.? creation? of? multiple? ? ? ? ? ? ? different? devices. It's not adviced to combine different opera-? ? ? ? ? ? ? tions on the single device.? ? ? -u|--uuid? ? ? ? ? ? ? Specify the uuid.? ? ? -y|--yes? ? ? clear device_name? ? ? ? ? ? ? Destroys the table in the inactive table slot for device_name.? ? ? create device_name [-u|--uuid uuid]? ? ? ? ? ? ? [--addnodeoncreate|--addnodeonresume] [-n|--notable|--table? ? ? ? ? ? ? table|table_file] [--readahead [+]sectors|auto|none]? ? ? ? ? ? ? Creates a device with the given name.? If table or table_file is? ? ? ? ? ? ? supplied,? the table is loaded and made live.? Otherwise a table? ? ? ? ? ? ? is read from standard? input? unless? --notable? is? used.? The? ? ? ? ? ? ? optional? uuid can be used in place of device_name in subsequent? ? ? ? ? ? ? dmsetup commands.? If successful the device will appear in table? ? ? ? ? ? ? and for live device the node /dev/mapper/device_name is created.? ? ? ? ? ? ? See below for more information on the table format.? ? ? create --concise [concise_device_specification]? ? ? ? ? ? ? Creates one or more devices from a concise device specification.? ? ? ? ? ? ? Each? device is specified by a comma-separated list: name, uuid,? ? ? ? ? ? ? minor? number,? flags,? comma-separated? table? lines.? ? Flags? ? ? ? ? ? ? defaults? to? read-write? (rw)? or may be read-only (ro).? Uuid,? ? ? ? ? ? ? minor number and flags are? optional? so? those? fields? may? be? ? ? ? ? ? ? empty.? A? semi-colon? separates? specifications? of? different? ? ? ? ? ? ? devices.? Use a backslash to escape the following character, for? ? ? ? ? ? ? example? a comma or semi-colon in a name or table. See also CON-? ? ? ? ? ? ? CISE FORMAT below.? ? ? deps [-o options] [device_name...]? ? ? ? ? ? ? Outputs a list of devices referenced by the live table? for? the? ? ? ? ? ? ? specified? device.? Device? names on output can be customised by? ? ? ? ? ? ? following? options:? devno? (major? and? minor? pair,? used? by? ? ? ? ? ? ? default),? blkdevname (block device name), devname (map name for? ? ? ? ? ? ? device-mapper devices, equal to blkdevname otherwise).? ? ? help [-c|-C|--columns]? ? ? ? ? ? ? Outputs a summary of the commands available, optionally? includ-? ? ? ? ? ? ? ing the list of report fields.? ? ? info [device_name...]? ? ? ? ? ? ? Outputs some brief information about the device in the form:? ? ? ? ? ? ? ? ? ? ? State: SUSPENDED|ACTIVE, READ-ONLY? ? ? ? ? ? ? ? ? ? ? Tables present: LIVE and/or INACTIVE? ? ? ? ? ? ? ? ? ? ? Open reference count? ? ? ? ? ? ? ? ? ? ? Last event sequence number (used by wait)? ? ? ? ? ? ? ? ? ? ? Major and minor device number? ? ? ? ? ? ? ? ? ? ? Number of targets in the live table? ? ? ? ? ? ? ? ? ? ? UUID? ? ? info -c|-C|--columns [--count count] [--interval seconds]? ? ? ? ? ? ? [--nameprefixes] [--noheadings] [-o fields] [-O|--sort? ? ? ? ? ? ? sort_fields] [--separator separator] [device_name]? ? ? ? ? ? ? Output you can customise.? Fields are comma-separated and chosen? ? ? ? ? ? ? from the following list: name, major, minor,? attr,? open,? seg-? ? ? ? ? ? ? ments,? events,? uuid.? Attributes? are:? (L)ive,? (I)nactive,? ? ? ? ? ? ? comma-separate? list? of? options.? Some specify the information? ? ? ? ? ? ? displayed? against? each? node:? device/nodevice;? blkdevname;? ? ? ? ? ? ? active,? open,? rw,? uuid.? Others specify how the tree is dis-? ? ? ? ? ? ? played: ascii, utf, vt100; compact, inverted, notrunc.? ? ? load|reload device_name [--table table|table_file]? ? ? ? ? ? ? Loads table or table_file? into? the? inactive? table? slot? for? ? ? ? ? ? ? device_name.? If? neither is supplied, reads a table from stan-? ? ? ? ? ? ? dard input.? ? ? mangle [device_name...]? ? ? ? ? ? ? Ensure existing device-mapper device_name and? UUID? is? in? the? ? ? ? ? ? ? correct? mangled? form? containing? only? whitelisted characters? ? ? ? ? ? ? (supported by udev) and do a rename if necessary. Any? character? ? ? ? ? ? ? not? on? the whitelist will be mangled based on the --manglename? ? ? ? ? ? ? setting. Automatic rename works only for device? names? and? not? ? ? ? ? ? ? for? device UUIDs because the kernel does not allow changing the? ? ? ? ? ? ? UUID of active devices. Any incorrect UUIDs? are? reported? only? ? ? ? ? ? ? and? they? must be manually corrected by deactivating the device? ? ? ? ? ? ? first and then reactivating it with proper? mangling? mode? used? ? ? ? ? ? ? (see also --manglename).? ? ? message device_name sector message? ? ? ? ? ? ? Send message to target. If sector not needed use 0.? ? ? mknodes [device_name...]? ? ? ? ? ? ? Ensure? that the node in /dev/mapper for device_name is correct.? ? ? ? ? ? ? If? no? device_name? is? supplied,? ensure? that? all? nodes? in? ? ? ? ? ? ? /dev/mapper correspond to mapped devices currently loaded by the? ? ? ? ? ? ? device-mapper kernel driver, adding, changing or removing? nodes? ? ? ? ? ? ? as necessary.? ? ? remove [-f|--force] [--retry] [--deferred] device_name...? ? ? ? ? ? ? Removes? a? device.? It? will? no longer be visible to dmsetup.? ? ? ? ? ? ? Open devices cannot be removed, but adding --force will? replace? ? ? ? ? ? ? the? table? with one that fails all I/O.? --deferred will enable? ? ? ? ? ? ? deferred removal of open devices - the device? will? be? removed? ? ? ? ? ? ? when? the? last? user closes it. The deferred removal feature is? ? ? ? ? ? ? supported since? version? 4.27.0? of? the? device-mapper? driver? ? ? ? ? ? ? available in upstream kernel version 3.13.? (Use dmsetup version? ? ? ? ? ? ? to check this.)? If an attempt to remove a device fails, perhaps? ? ? ? ? ? ? because? a process run from a quick udev rule temporarily opened? ? ? ? ? ? ? the device, the --retry option will cause the? operation? to? be? ? ? ? ? ? ? retried? for? a? few? seconds? before? failing.? Do NOT combine? ? ? ? ? ? ? --force and --udevcookie, as udev? may? start? to? process? udev? ? ? ? ? ? ? rules? in? the? middle of error target replacement and result in? ? ? ? ? ? ? nondeterministic result.? ? ? remove_all [-f|--force] [--deferred]? ? ? ? ? ? ? Attempts to remove all device definitions i.e. reset the driver.? ? ? ? ? ? ? This also runs mknodes afterwards.? Use with care!? Open devices? ? ? ? ? ? ? cannot be removed, but adding --force? will? replace? the? table? ? ? ? ? ? ? [--noflush] [--nolockfs] [--readahead [+]sectors|auto|none]? ? ? ? ? ? ? Un-suspends? a device.? If an inactive table has been loaded, it? ? ? ? ? ? ? becomes live.? Postponed I/O then gets re-queued for processing.? ? ? setgeometry device_name cyl head sect start? ? ? ? ? ? ? Sets the device geometry to C/H/S.? ? ? splitname device_name [subsystem]? ? ? ? ? ? ? Splits given? device? name? into? subsystem? constituents.? The? ? ? ? ? ? ? default? subsystem is LVM.? LVM currently generates device names? ? ? ? ? ? ? by concatenating the names of the Volume Group,? Logical? Volume? ? ? ? ? ? ? and? any internal Layer with a hyphen as separator.? Any hyphens? ? ? ? ? ? ? within the names are doubled to escape them.? The precise encod-? ? ? ? ? ? ? ing? might? change? without? notice in any future release, so we? ? ? ? ? ? ? recommend you always decode using the current? version? of? this? ? ? ? ? ? ? command.? ? ? stats command [options]? ? ? ? ? ? ? Manages? IO? statistics regions for devices.? Seedmstats(8)for? ? ? ? ? ? ? more details.? ? ? status [--target target_type] [--noflush] [device_name...]? ? ? ? ? ? ? Outputs status information for each? of? the? device's? targets.? ? ? ? ? ? ? With --target, only information relating to the specified target? ? ? ? ? ? ? type any is displayed.? With --noflush, the? thin? target? (from? ? ? ? ? ? ? version? 1.3.0)? doesn't? commit any outstanding changes to disk? ? ? ? ? ? ? before reporting its statistics.? ? ? suspend [--nolockfs] [--noflush] device_name...? ? ? ? ? ? ? Suspends a device.? Any I/O that has already been mapped by? the? ? ? ? ? ? ? device? but? has not yet completed will be flushed.? Any further? ? ? ? ? ? ? I/O to that device will be postponed for as long as? the? device? ? ? ? ? ? ? is? suspended.? If there's a filesystem on the device which sup-? ? ? ? ? ? ? ports the operation, an attempt will be made to? sync? it? first? ? ? ? ? ? ? unless? --nolockfs? is? specified.? Some targets such as recent? ? ? ? ? ? ? (October 2006) versions of multipath may support? the? --noflush? ? ? ? ? ? ? option.? This lets outstanding I/O that has not yet reached the? ? ? ? ? ? ? device to remain unflushed.? ? ? table [--concise] [--target target_type] [--showkeys] [device_name...]? ? ? ? ? ? ? Outputs the current table for the device in a format that can be? ? ? ? ? ? ? fed? back? in using the create or load commands.? With --target,? ? ? ? ? ? ? only information relating to the specified target type? is? dis-? ? ? ? ? ? ? played.? Real encryption keys are suppressed in the table output? ? ? ? ? ? ? for crypt and integrity targets unless the --showkeys? parameter? ? ? ? ? ? ? is? supplied.? Kernel? key? references? prefixed? with : are not? ? ? ? ? ? ? affected by the parameter and get displayed always (crypt target? ? ? ? ? ? ? only).? With? --concise, the output is presented concisely on a? ? ? ? ? ? ? single line.? Commas then separate the name, uuid, minor? device? ? ? ? ? ? ? number,? flags? ('ro' or 'rw') and the table (if present). Semi-? ? ? ? ? ? ? colons separate devices. Backslashes escape? any? commas,? semi-? ? ? ? ? ? ? List? all? existing? cookies. Cookies are system-wide semaphores? ? ? ? ? ? ? with keys prefixed by two predefined bytes (0x0D4D).? ? ? udevcreatecookie? ? ? ? ? ? ? Creates a new cookie to synchronize actions with? udev? process-? ? ? ? ? ? ? ing.? The? output? is a cookie value. Normally we don't need to? ? ? ? ? ? ? create cookies since dmsetup creates and destroys them for? each? ? ? ? ? ? ? action automatically. However, we can generate one explicitly to? ? ? ? ? ? ? group several actions together and use only one cookie? instead.? ? ? ? ? ? ? We can define a cookie to use for each relevant command by using? ? ? ? ? ? ? --udevcookie option. Alternatively, we? can? export? this? value? ? ? ? ? ? ? into? the? environment? of the dmsetup process as DM_UDEV_COOKIE? ? ? ? ? ? ? variable and it will be used automatically with? all? subsequent? ? ? ? ? ? ? commands? until? it is unset.? Invoking this command will create? ? ? ? ? ? ? system-wide semaphore that needs to be cleaned up explicitly? by? ? ? ? ? ? ? calling udevreleasecookie command.? ? ? udevflags cookie? ? ? ? ? ? ? Parses? given? cookie? value and extracts any udev control flags? ? ? ? ? ? ? encoded.? The output is in environment key format that is? suit-? ? ? ? ? ? ? able? for? use? in udev rules. If the flag has its symbolic name? ? ? ? ? ? ? assigned then the? output? is? DM_UDEV_FLAG_? =? '1',? ? ? ? ? ? ? DM_UDEV_FLAG? =? '1'? otherwise.? Subsystem udev? ? ? ? ? ? ? flags don't have symbolic names? assigned? and? these? ones? are? ? ? ? ? ? ? always? reported as DM_SUBSYSTEM_UDEV_FLAG = '1'.? ? ? ? ? ? ? There are 16 udev flags altogether.? ? ? udevreleasecookie [cookie]? ? ? ? ? ? ? Waits for all pending udev? processing? bound? to? given? cookie? ? ? ? ? ? ? value? and clean up the cookie with underlying semaphore. If the? ? ? ? ? ? ? cookie is not given directly, the command? will? try? to? use? a? ? ? ? ? ? ? value defined by DM_UDEV_COOKIE environment variable.? ? ? version? ? ? ? ? ? ? Outputs version information.? ? ? wait [--noflush] device_name [event_nr]? ? ? ? ? ? ? Sleeps until the event counter for device_name exceeds event_nr.? ? ? ? ? ? ? Use -v to see the event number returned.? To wait until the next? ? ? ? ? ? ? event? is? triggered,? use? info? to find the last event number.? ? ? ? ? ? ? With --noflush, the thin target? (from? version? 1.3.0)? doesn't? ? ? ? ? ? ? commit any outstanding changes to disk before reporting its sta-? ? ? ? ? ? ? tistics.? ? ? wipe_table device_name...? [-f|--force] [--noflush] [--nolockfs]? ? ? ? ? ? ? Wait for any I/O in-flight through the device to complete,? then? ? ? ? ? ? ? replace? the? table with a new table that fails any new I/O sent? ? ? ? ? ? ? to the device.? If successful, this should release? any? devices? ? ? ? ? ? ? held open by the device's table(s).

TABLE FORMAT

Each line of the table specifies a single target and is of the form:? ? ? ? ? ? ? ? ? ? ? LV chunk 3-> hda1, chunk 2? ? ? ? ? ? ? ? ? ? ? LV chunk 4-> hdb1, chunk 2? ? ? ? ? ? ? ? ? ? ? etc.? ? ? error? Errors any I/O that goes to this area.? Useful? for? testing? or? ? ? ? ? ? ? for creating devices with holes in them.? ? ? zero? Returns? blocks? of? zeroes? on reads.? Any data written is dis-? ? ? ? ? ? ? carded silently.? This? is? a? block-device? equivalent? of? the? ? ? ? ? ? ? /dev/zero character-device data sink described innull(4).? ? ? More complex targets include:? ? ? cache? Improves performance of a block device (eg, a spindle) by dynam-? ? ? ? ? ? ? ically migrating some of its data to? a? faster? smaller? device? ? ? ? ? ? ? (eg, an SSD).? ? ? crypt? Transparent? encryption of block devices using the kernel crypto? ? ? ? ? ? ? API.? ? ? delay? Delays reads and/or writes to? different? devices.? Useful? for? ? ? ? ? ? ? testing.? ? ? flakey Creates? a? similar? mapping? to? the linear target but exhibits? ? ? ? ? ? ? unreliable behaviour periodically.? Useful for simulating? fail-? ? ? ? ? ? ? ing devices when testing.? ? ? mirror Mirrors data across two or more devices.? ? ? multipath? ? ? ? ? ? ? Mediates access through multiple paths to the same device.? ? ? raid? Offers an interface to the kernel's software raid driver, md.? ? ? snapshot? ? ? ? ? ? ? Supports snapshots of devices.? ? ? thin, thin-pool? ? ? ? ? ? ? Supports thin provisioning of devices and also provides a better? ? ? ? ? ? ? snapshot support.? ? ? To find out more about the various targets and their table formats? and? ? ? status? lines, please read the files in the Documentation/device-mapper? ? ? directory in the kernel source tree.? (Your distribution might? include? ? ? a? copy? of? this? information? in? the documentation directory for the? ? ? device-mapper package.)

EXAMPLES

? ? ? # A table to join two disks together

? ? ? 0 1028160 linear /dev/hda 0

? ? ? 1028160 3903762 linear /dev/hdb 0

? ? ? # A table to stripe across the two disks,

? ? ? ? ? ? ? ble>+][;<dev_name>,<uuid>,<minor>,<flags>,<table>[,<table>+]]

? ? ? The fields are:

? ? ? name? The name of the device.

? ? ? uuid? The UUID of the device (or empty).

? ? ? minor? The? minor number of the device.? If empty, the kernel assigns a

? ? ? ? ? ? ? suitable minor number.

? ? ? flags? Supported flags are:

? ? ? ? ? ? ? ro Sets the table being loaded for the device read-only

? ? ? ? ? ? ? rw Sets? the? table? being? loaded? for? the? device? read-write

? ? ? ? ? ? ? (default)

? ? ? table? One line of the table. See TABLE FORMAT above.

EXAMPLES

? ? ? # A simple linear read-only device

? ? ? test-linear-small,,,ro,0? 2097152? linear /dev/loop0 0, 2097152 2097152

? ? ? linear /dev/loop1 0

? ? ? # Two linear devices

? ? ? test-linear-small,,,,0? 2097152? ? linear? ? /dev/loop0? ? 0;test-lin-

? ? ? ear-large,,,,? 0? 2097152? linear? /dev/loop1 0, 2097152 2097152 linear

? ? ? /dev/loop2 0

ENVIRONMENT VARIABLES

? ? ? DM_DEV_DIR

? ? ? ? ? ? ? The device directory name.? Defaults to "/dev" and? must? be? an

? ? ? ? ? ? ? absolute path.

? ? ? DM_UDEV_COOKIE

? ? ? ? ? ? ? A? cookie? to? use for all relevant commands to synchronize with

? ? ? ? ? ? ? udev processing.? It is an? alternative? to? using? --udevcookie

? ? ? ? ? ? ? option.

? ? ? DM_DEFAULT_NAME_MANGLING_MODE

? ? ? ? ? ? ? A? default mangling mode. Defaults to "auto" and it is an alter-

? ? ? ? ? ? ? native to using --manglename option.

AUTHORS

? ? ? Original version: Joe Thornber <thornber@redhat.com>

SEE ALSO

dmstats(8),udev(7),udevadm(8)LVM2 resource page: https://www.sourceware.org/lvm2/? ? ? Device-mapper resource page: http://sources.redhat.com/dm/