--alias name
Specify an alias name for a group.
--alldevices
If no device arguments are given allow operation on all
devices when creating or deleting regions.
--allprograms
Include regions from all program IDs for list and report
operations.
--allregions
Include all present regions for commands that normally
accept a single region identifier.
--area When peforming a list or report, include objects of type
area in the results.
--areas nr_areas
Specify the number of statistics areas to create within a
new region.
--areasize area_size[b|B|s|S|k|K|m|M|g|G|t|T|p|P|e|E]
Specify the size of areas into which a new region should
be divided. An optional suffix selects units of: (b)ytes,
(s)ectors, (k)ilobytes, (m)egabytes, (g)igabytes,
(t)erabytes, (p)etabytes, (e)xabytes. Capitalise to use
multiples of 1000 (S.I.) instead of 1024.
--clear
When printing statistics counters, also atomically reset
them to zero.
--count count
Specify the iteration count for repeating reports. If the
count argument is zero reports will continue to repeat
until interrupted.
--group
When peforming a list or report, include objects of type
group in the results.
--filemap
Instead of creating regions on a device as specified by
command line options, open the file found at each
file_path argument, and create regions corresponding to
the locations of the on-disk extents allocated to the
file(s).
--nomonitor
Disable the dmfilemapd daemon when creating new file
mapped groups. Normally the device-mapper filemap
monitoring daemon, dmfilemapd, is started for each file
mapped group to update the set of regions as the file
changes on-disk: use of this option disables this
behaviour.
Regions in the group may still be updated with the
update_filemap command, or by starting the daemon
manually.
--follow follow_mode
Specify the dmfilemapd file following mode. The file map
monitoring daemon can monitor files in two distinct ways:
the mode affects the behaviour of the daemon when a file
under monitoring is renamed or unlinked, and the
conditions which cause the daemon to terminate.
The follow_mode argument is either "inode", for follow-
inode mode, or "path", for follow-path.
If follow-inode mode is used, the daemon will hold the
file open, and continue to update regions from the same
file descriptor. This means that the mapping will follow
rename, move (within the same file system), and unlink
operations. This mode is useful if the file is expected to
be moved, renamed, or unlinked while it is being
monitored.
In follow-inode mode, the daemon will exit once it detects
that the file has been unlinked and it is the last holder
of a reference to it.
If follow-path is used, the daemon will re-open the
provided path on each monitoring iteration. This means
that the group will be updated to reflect a new file being
moved to the same path as the original file. This mode is
useful for files that are expected to be updated via
unlink and rename.
In follow-path mode, the daemon will exit if the file is
removed and not replaced within a brief tolerance
interval.
In either mode, the daemon exits automatically if the
monitored group is removed.
--foreground
Specify that the dmfilemapd daemon should run in the
foreground. The daemon will not fork into the background,
and will replace the dmstats command that started it.
--groupid id
Specify the group to operate on.
--bounds histogram_boundaries[ns|us|ms|s]
Specify the boundaries of a latency histogram to be
tracked for the region as a comma separated list of
latency values. Latency values are given in nanoseconds.
An optional unit suffix of ns,us,ms, or s may be given
after each value to specify units of nanoseconds,
microseconds, miliseconds or seconds respectively.
--histogram
When used with the report and list commands select default
fields that emphasize latency histogram data.
--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.
--length length[b|B|s|S|k|K|m|M|g|G|t|T|p|P|e|E]
Specify the length of a new statistics region in sectors.
An optional suffix selects units of: (b)ytes, (s)ectors,
(k)ilobytes, (m)egabytes, (g)igabytes, (t)erabytes,
(p)etabytes, (e)xabytes. Capitalise to use multiples of
1000 (S.I.) instead of 1024.
-j|--major major
Specify the major number.
-m|--minor minor
Specify the minor number.
--nogroup
When creating regions mapping the extents of a file in the
file system, do not create a group or set an alias.
--nosuffix
Suppress the suffix on output sizes. Use with --units
(except h and H) if processing the output.
--notimesuffix
Suppress the suffix on output time values. Histogram
boundary values will be reported in units of nanoseconds.
-o|--options
Specify which report fields to display.
-O|--sort sort_fields
Sort output according to the list of fields given. Precede
any sort field with '-' for a reverse sort on that column.
--precise
Attempt to use nanosecond precision counters when creating
new statistics regions.
--programid id
Specify a program ID string. When creating new statistics
regions this string is stored with the region. Subsequent
operations may supply a program ID in order to select only
regions with a matching value. The default program ID for
dmstats-managed regions is "dmstats".
--region
When peforming a list or report, include objects of type
region in the results.
--regionid id
Specify the region to operate on.
--regions region_list
Specify a list of regions to group. The group list is a
comma-separated list of region identifiers. Continuous
sequences of identifiers may be expressed as a hyphen
separated range, for example: '1-10'.
--relative
If displaying the histogram report show relative
(percentage) values instead of absolute counts.
-S|--select selection
Display only rows that match selection criteria. All rows
with the additional "selected" column (-o selected)
showing 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.
--start start[b|B|s|S|k|K|m|M|g|G|t|T|p|P|e|E]
Specify the start offset of a new statistics region in
sectors. An optional suffix selects units of: (b)ytes,
(s)ectors, (k)ilobytes, (m)egabytes, (g)igabytes,
(t)erabytes, (p)etabytes, (e)xabytes. Capitalise to use
multiples of 1000 (S.I.) instead of 1024.
--segments
When used with create, create a new statistics region for
each target contained in the given device(s). This causes
a separate region to be allocated for each segment of the
device.
The newly created regions are automatically placed into a
group unless the --nogroup option is given. When grouping
is enabled a group alias may be specified using the
--alias option.
--units [units][h|H|b|B|s|S|k|K|m|M|g|G|t|T|p|P|e|E]
Set the display units for report output. All sizes are
output in these units: (h)uman-readable, (b)ytes,
(s)ectors, (k)ilobytes, (m)egabytes, (g)igabytes,
(t)erabytes, (p)etabytes, (e)xabytes. Capitalise to use
multiples of 1000 (S.I.) instead of 1024. Can also
specify custom units e.g. --units 3M.
--userdata user_data
Specify user data (a word) to be stored with a new region.
The value is added to any internal auxiliary data (for
example, group information), and stored with the region in
the aux_data field provided by the kernel. Whitespace is
not permitted.
-u|--uuid
Specify the uuid.
-v|--verbose [-v|--verbose]
Produce additional output.
