NAME
dmvdostats — Display VDO statistics for device-mapper devices
SYNOPSIS
dmvdostats [-h|--help] [-v|--verbose] [--count count] [--interval seconds] [-o|--options fields] [-O|--sort sort_fields] [-S|--select selection] [--noheadings] [--nosuffix] [--separator separator] [--units units] [device...]
dmsetup vdostats [options] [device...]
DESCRIPTION
dmvdostats displays statistics for VDO (Virtual Data Optimizer) device-mapper targets. It queries each VDO device via the kernel stats message interface and presents the results in either a tabular (report) format or a verbose key-value format.
If no device argument is given, dmvdostats enumerates all device-mapper devices and reports statistics for every VDO target found.
A device argument may name a VDO device directly, or any device-mapper device layered above one (for example an LVM VDO logical volume, or a thin logical volume whose pool data is a VDO). In that case dmvdostats descends the device dependency tree and reports statistics for every underlying VDO device found. As a convenience, a name that does not resolve to any device is retried with the LVM -vpool suffix appended, so the hidden VDO pool device can be named by its pool logical volume name.
dmvdostats is installed as a symlink to dmsetup(8) and may also be invoked as dmsetup vdostats.
OPTIONS
- -h, --help
-
Display usage information.
- -v, --verbose
-
Produce verbose output. Instead of the tabular report, display all kernel statistics in a key-value format compatible with the legacy vdostats tool. Derived fields (1K-blocks, used percent, saving percent, write amplification) are inserted into the output.
- --count count
-
Repeat the report count times. Use with --interval to monitor VDO statistics continuously.
- --interval seconds
-
Pause seconds between report iterations when --count is greater than one.
- -o, --options fields
-
Comma-separated list of fields to display. Use -o help to see a list of available fields. If not specified, the default fields are:
vdo_name,vdo_physical_size,vdo_used, vdo_available,vdo_used_pct,vdo_saving_pct.
- -O, --sort sort_fields
-
Comma-separated list of fields to sort by.
- -S, --select selection
-
Display only rows that match the selection criteria. See lvmreport(7) for the selection syntax.
- --noheadings
-
Suppress the headings line in report output.
- --nosuffix
-
Suppress the suffix on size values.
- --separator separator
-
Use separator between fields in report output.
- --units units
-
Set the display unit for size fields. Available units: b(ytes), s(ectors), k(ilobytes), m(egabytes), g(igabytes), t(erabytes), p(etabytes), e(xabytes). Capitalize to use multiples of 1000 (S.I.) instead of 1024. Default is human-readable (h).
FIELDS
The following fields are available for report output (-o):
- vdo_name
-
VDO device name.
- vdo_physical_size
-
Physical size of the VDO device.
- vdo_used
-
Physical space used (data blocks + overhead).
- vdo_available
-
Physical space available.
- vdo_used_pct
-
Percentage of physical space used.
- vdo_saving_pct
-
Percentage of logical data saved by deduplication and compression.
- vdo_all
-
All VDO fields.
EXAMPLES
Display default statistics for all VDO devices:
# dmvdostats
Display verbose output for a specific device:
# dmvdostats -v /dev/mapper/vg-vpool0-vpool
Display selected fields:
# dmvdostats -o vdo_name,vdo_used_pct,vdo_saving_pct
Monitor usage every 5 seconds, 10 times:
# dmvdostats --count 10 --interval 5
Filter to devices over 50% usage:
# dmvdostats -S 'vdo_used_pct > 50'