#
# Copyright (c) 2015,2017 Red Hat.
#
# This program is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the
# Free Software Foundation; either version 2 of the License, or (at your
# option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
# or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
# for more details.
#
# Device Mapper PMDA help file in the ASCII format
#
# lines beginning with a # are ignored
# lines beginning @ introduce a new entry of the form
#  @ metric_name oneline-text
#  help text goes
#  here over multiple lines
#  ...
#
# the metric_name is decoded against the default PMNS -- as a special case,
# a name of the form NNN.MM (for numeric NNN and MM) is interpreted as an
# instance domain identification, and the text describes the instance domain
#
# blank lines before the @ line are ignored
#
@ DM.0 Device mapper cache block devices
@ DM.1 Device mapper thin provisioning pools
@ DM.2 Device mapper thin provisioning volumes
@ DM.3 Device mapper latency histogram bins

@ dmcache.size Size of each cache device
The total size of each cache device in Kbytes.

@ dmcache.metadata.block_size Block size for metadata
The fixed block size for each metadata block in bytes.

@ dmcache.metadata.used Metadata block used
The number of metadata blocks used.

@ dmcache.metadata.total Total metadata blocks
The total number of metadata blocks.

@ dmcache.cache.block_size Block size for cache
The fixed block size of each cache block in bytes.

@ dmcache.cache.used Cache blocks used
The number of cache blocks used.

@ dmcache.cache.total Total cache blocks
The total number of cache blocks.

@ dmcache.read_hits Read bio mapping cache
Number of times a READ bio has been mapped to the cache.

@ dmcache.read_misses Read bio mapping origin
Number of times a READ bio has been mapped to the origin.

@ dmcache.write_hits Write bio mapping cache
Number of times a WRITE bio has been mapped to the cache.

@ dmcache.write_misses Write bio mapping origin
Number of times a WRITE bio has been mapped to the origin.

@ dmcache.demotions Block removed from cache
Number of times a block has been removed from the cache.

@ dmcache.promotions Block moved to cache
Number of times a block has been moved to the cache.

@ dmcache.dirty Blocks different to origin
Number of blocks in the cache that differ from the origin.

@ dmcache.io_mode_code Cache mode
Cache mode code - writeback, writethrough, passthrough.

@ dmcache.io_mode Cache mode
Cache mode string - writeback, writethrough or passthrough.

@ dmthin.pool.size Size of each pool device
The total size of each pool device in Kbytes.

@ dmthin.pool.transaction_id Sync number with volume manager
Number used by userspace to help synchronise with metadata
from volume managers.

@ dmthin.pool.metadata.used Number of metadata blocks used
The number of metadata blocks which are currently in use.

@ dmthin.pool.metadata.total Total number of metadata blocks
The total number of metadata blocks for the given thin storage pool.

@ dmthin.pool.data.used Number of data blocks used
The number of data blocks which are currently in use.

@ dmthin.pool.data.total Total number of data blocks
The total number of data blocks for the given thin storage pool.

@ dmthin.pool.held_root Location of metadata root
The location in blocks of the metadata root that has been 'held' for
userspace read access. "-" indicates that there is no held root.

@ dmthin.pool.discard_passdown Discards passed or not
Whether or not discards are being passed down to the underlying device.

@ dmthin.pool.read_mode Read mode of the thin pool
Indication of whether the pool is in read/write mode or read only mode.
In the event that the pool encounters certain types of device failures
it will drop into read-only metadata mode.

@ dmthin.pool.no_space_mode Mode used when pool is out of space
If the pool runs out of data or metadata space, the pool will fallback
to either queuing or error any IO destined to the data device. The
default is to queue until more space is added to the pool.

@ dmthin.vol.size Size of each thin volume
The total size of each thin volume in Kbytes.

@ dmthin.vol.num_mapped_sectors Number of sectors mapped
The total number of mapped sectors to the thin volume.

@ dmthin.vol.highest_mapped_sector Highest mapped sector
The highest mapped sector of the thin volume.

@ dmstats.read The number of reads completed
Count of reads completed this interval per dm device.

@ dmstats.reads_merged The number of reads merged
Count of reads merged this interval per dm device.

@ dmstats.read_bytes The number of kbyte read
Count of kbyte read this inteval per dm device.

@ dmstats.reads_time The number of nanoseconds spent reading
Accumulated duration of all read request per dm device.

@ dmstats.write The number of writes completed
Count of writes completed this interval per dm-device.

@ dmstats.writes_merged The number of writes merged
Count of writes merged this interval per dm device.

@ dmstats.write_bytes The number of kbyte written
Count of kbytes writes this interval per dm-device.

@ dmstats.writes_time The number of nanoseconds spent writing
Accumulated duration of all write requests per dm device.

@ dmstats.in_progress The number of I/Os
Count of requests currently in progress per dm device.

@ dmstats.io_ticks The number of nanoseconds spend doing I/Os
Nanoseconds spent servicing requestst per dm device.

@ dmstats.queue_ticks The weighted number of nanoseconds spend doing I/Os
This field is incremented at each I/O start, I/O completion, I/O merge,
or read of these stats by the number of I/Os in progress multiplied by
the number of nanoseconds spent doing I/O since the last update of
this field. This can provide an easy measure of both I/O completion time
and the backlog that may be accumulating.

@ dmstats.read_ticks The total time spent reading
Nanoseconds spent servicing reads per dm device.

@ dmstats.write_ticks The total time spent writing
Nanoseconds spent servicing writes per dm device.

@dmstats.histogram.hist_count The list of histogram counts
A list of the histogram counts for the current statistics region in order
of ascending value. The instance name includes bin boundaries.

@dmstats.histogram.hist_bins The number of latency histogram bins
The number of latency histogram bins configured for the region.
