Ubuntu Manpage: vdostats - Display configuration and statistics of VDO volumes

NAME

       vdostats - Display configuration and statistics of VDO volumes

SYNOPSIS

       vdostats [options ...] [device [device ...]]

DESCRIPTION

       vdostats  displays  configuration and statistics information for the given VDO devices. If no devices are
       given, it displays information about all VDO devices.

       The VDO devices must be running in order for configuration and statistics
              information to be reported.

OPTIONS

       -h, --help
              Show help message and exit.

       -a, --all
              This option is only for backwards compatibility. It is now equivalent to --verbose.

       --human-readable
              Display block values in readable form (Base 2: 1 KB = 2^10 bytes = 1024 bytes).

       --si   Modifies the output of the --human-readable option to use SI units (Base 10: 1 KB = 10^3  bytes  =
              1000 bytes). If the --human-readable option is not supplied, this option has no effect.

       -v, --verbose
              Displays the utilization and block I/O (bios) statistics for the selected VDO devices.

       -V, --version
              Prints the vdostats version number and exits

OUTPUT

       The default output format is a table with the following columns, similar to that of the Linux df utility:

       Device The path to the VDO volume

       1K-blocks
              The  total  number  of 1K blocks allocated for a VDO volume (= physical volume size * block size /
              1024)

       Used   The total number of 1K blocks used on a VDO volume (= physical blocks used * block size / 1024)

       Available
              The total number of 1K blocks available on a VDO volume (= physical blocks free  *  block  size  /
              1024)

       Use%   The percentage of physical blocks used on a VDO volume (= used blocks / allocated blocks * 100)

       Space Saving%
              The  percentage of physical blocks saved on a VDO volume (= [logical blocks used - physical blocks
              used] / logical blocks used)

VERBOSE OUTPUT

The --verbose option displays VDO device statistics in YAML format for the specified VDO devices. The
following fields will continue to be reported in future releases. Management tools should not rely upon
the order in which any of the statistics are reported.

version
The version of these statistics.

release version
The release version of the VDO.

data blocks used
The number of physical blocks currently in use by a VDO volume to store data.

overhead blocks used
The number of physical blocks currently in use by a VDO volume to store VDO metadata.

logical blocks used
The number of logical blocks currently mapped.

physical blocks
The total number of physical blocks allocated for a VDO volume.

logical blocks
The maximum number of logical blocks that can be mapped by a VDO volume.

1K-blocks
The total number of 1K blocks allocated for a VDO volume (= physical volume size * block size /
1024)

1K-blocks used
The total number of 1K blocks used on a VDO volume (= physical blocks used * block size / 1024)

1K-blocks available
The total number of 1K blocks available on a VDO volume (= physical blocks free * block size /
1024)

used percent
The percentage of physical blocks used on a VDO volume (= used blocks / allocated blocks * 100)

saving percent
The percentage of physical blocks saved on a VDO volume (= [logical blocks used - physical blocks
used] / logical blocks used)

block map cache size
The size of the block map cache, in bytes.

write policy
The write policy (sync, async, or async-unsafe). This is configured via vdo modify
--writePolicy=policy.

block size
The block size of a VDO volume, in bytes.

completed recovery count
The number of times a VDO volume has recovered from an unclean shutdown.

read-only recovery count
The number of times a VDO volume has been recovered from read-only mode (via vdo start
--forceRebuild).

operating mode
Indicates whether a VDO volume is operating normally, is in recovery mode, or is in read-only
mode.

recovery progress (%)
Indicates online recovery progress, or N/A if the volume is not in recovery mode.

compressed fragments written
The number of compressed fragments that have been written since the VDO volume was last restarted.

compressed blocks written
The number of physical blocks of compressed data that have been written since the VDO volume was
last restarted.

The remaining fields are primarily intended for software support and are subject to change in future
releases; management tools should not rely upon them.

compressed fragments in packer
The number of compressed fragments being processed that have not yet been written.

slab count
The total number of slabs.

slabs opened
The total number of slabs from which blocks have ever been allocated.

slabs reopened
The number of times slabs have been re-opened since the VDO was started.

journal disk full count
The number of times a request could not make a recovery journal entry because the recovery journal
was full.

journal commits requested count
The number of times the recovery journal requested slab journal commits.

journal entries batching
The number of journal entry writes started minus the number of journal entries written.

journal entries started
The number of journal entries which have been made in memory.

journal entries writing
The number of journal entries in submitted writes minus the number of journal entries committed to
storage.

journal entries written
The total number of journal entries for which a write has been issued.

journal entries committed
The number of journal entries written to storage.

journal blocks batching
The number of journal block writes started minus the number of journal blocks written.

journal blocks started
The number of journal blocks which have been touched in memory.

journal blocks writing
The number of journal blocks written (with metadatata in active memory) minus the number of
journal blocks committed.

journal blocks written
The total number of journal blocks for which a write has been issued.

journal blocks committed
The number of journal blocks written to storage.

slab journal disk full count
The number of times an on-disk slab journal was full.

slab journal flush count
The number of times an entry was added to a slab journal that was over the flush threshold.

slab journal blocked count
The number of times an entry was added to a slab journal that was over the blocking threshold.

slab journal blocks written
The number of slab journal block writes issued.

slab journal tail busy count
The number of times write requests blocked waiting for a slab journal write.

slab summary blocks written
The number of slab summary block writes issued.

reference blocks written
The number of reference block writes issued.

block map dirty pages
The number of dirty pages in the block map cache.

block map clean pages
The number of clean pages in the block map cache.

block map free pages
The number of free pages in the block map cache.

block map failed pages
The number of block map cache pages that have write errors.

block map incoming pages
The number of block map cache pages that are being read into the cache.

block map outgoing pages
The number of block map cache pages that are being written.

block map cache pressure
The number of times a free page was not available when needed.

block map read count
The total number of block map page reads.

block map write count
The total number of block map page writes.

block map failed reads
The total number of block map read errors.

block map failed writes
The total number of block map write errors.

block map reclaimed
The total number of block map pages that were reclaimed.

block map read outgoing
The total number of block map reads for pages that were being written.

block map found in cache
The total number of block map cache hits.

block map discard required
The total number of block map requests that required a page to be discarded.

block map wait for page
The total number of requests that had to wait for a page.

block map fetch required
The total number of requests that required a page fetch.

block map pages loaded
The total number of page fetches.

block map pages saved
The total number of page saves.

block map flush count
The total number of flushes issued by the block map.

invalid advice PBN count
The number of times the index returned invalid advice

no space error count
The number of write requests which failed due to the VDO volume being out of space.

read only error count
The number of write requests which failed due to the VDO volume being in read-only mode.

instance
The VDO instance.

512 byte emulation
Indicates whether 512 byte emulation is on or off for the volume.

current VDO IO requests in progress
The number of I/O requests the VDO is current processing.

maximum VDO IO requests in progress
The maximum number of simultaneous I/O requests the VDO has processed.

current dedupe queries
The number of deduplication queries currently in flight.

maximum dedupe queries
The maximum number of in-flight deduplication queries.

dedupe advice valid
The number of times deduplication advice was correct.

dedupe advice stale
The number of times deduplication advice was incorrect.

dedupe advice timeouts
The number of times deduplication queries timed out.

concurrent data matches
The number of writes with the same data as another in-flight write.

concurrent hash collisions
The number of writes whose hash collided with an in-flight write.

flush out
The number of flush requests submitted by VDO to the underlying storage.

write amplification ratio
The average number of block writes to the underlying storage per block written to the VDO device.

bios in...
bios in partial...
bios out...
bios meta...
bios journal...
bios page cache...
bios out completed...
bios meta completed...
bios journal completed...
bios page cache completed...
bios acknowledged...
bios acknowledged partial...
bios in progress...
These statistics count the number of bios in each category with a given flag. The categories are:

bios in
The number of block I/O requests received by VDO.

bios in partial
The number of partial block I/O requests received by VDO. Applies only to 512-byte
emulation mode.

bios out
The number of non-metadata block I/O requests submitted by VDO to the storage device.

bios meta
The number of metadata block I/O requests submitted by VDO to the storage device.

bios journal
The number of recovery journal block I/O requests submitted by VDO to the storage device.

bios page cache
The number of block map I/O requests submitted by VDO to the storage device.

bios out completed
The number of non-metadata block I/O requests completed by the storage device.

bios meta completed
The number of metadata block I/O requests completed by the storage device.

bios journal completed
The number of recovery journal block I/O requests completed by the storage device.

bios page cache completed
The number of block map I/O requests completed by the storage device.

bios acknowledged
The number of block I/O requests acknowledged by VDO.

bios acknowledged partial
The number of partial block I/O requests acknowledged by VDO. Applies only to 512-byte
emulation mode.

bios in progress
The number of bios submitted to the VDO which have not yet been acknowledged.

There are five types of flags:

read The number of non-write bios (bios without the REQ_WRITE flag set)

write The number of write bios (bios with the REQ_WRITE flag set)

discard
The number of bios with a REQ_DISCARD flag set

flush The number of flush bios (bios with the REQ_FLUSH flag set)

fua The number of "force unit access" bios (bios with the REQ_FUA flag set)

Note that all bios will be counted as either read or write bios, depending on the REQ_WRITE flag
setting, regardless of whether any of the other flags are set.

KVDO module bytes used
The current count of bytes allocated by the kernel VDO module.

KVDO module peak bytes used
The peak count of bytes allocated by the kernel VDO module, since the module was loaded.

EXAMPLES

       The following example shows sample output if no options are provided:

       Device             1K-blocks  Used       Available   Use% Space Saving%
       /dev/mapper/my_vdo 1932562432 427698104  1504864328  22%  21%

       With the --human-readable option, block counts are converted to conventional units (1 KB = 1024 bytes):

       Device             Size   Used    Available   Use%   Space Saving%
       /dev/mapper/my_vdo 1.8T   407.9G  1.4T        22%    21%

       With the --si option as well, the block counts are reported using SI units (1 KB = 1000 bytes):

       Device             Size   Used    Available   Use%    Space Saving%
       /dev/mapper/my_vdo 2.0T   438G    1.5T        22%     21%

NOTES

       The output may be incomplete when the command is run by an unprivileged user.