200 Alphabetical list of commands
show vdisk-statistics
Description
Shows live or historical performance statistics for vdisks. This command applies to linear storage
only.
You can view live statistics for all or specified vdisks, or historical statistics for a specified vdisk. The
system samples disk-performance statistics every quarter hour and retains performance data for 6
months.
The
historical
option allows you to specify a time range or a number (count) of data samples to
include. It is not recommended to specify both the
time-range
and
count
parameters. If both
parameters are specified, and more samples exist for the specified time range, the samples' values
will be aggregated to show the required number of samples.
For each vdisk these statistics quantify destages, read-aheads, and host reads that are cache misses.
For example, each time data is written from a volume’s cache to disks in the vdisk that contains the
volume, the vdisk's statistics are adjusted.
Properties shown only in XML API format are described in
.
NOTE:
Values for the amount of data transferred and for data throughput appear to be much
higher in historical output than in live output. This is caused by a difference in the way that historical
and live values are calculated.
Live values are calculated based on the vdisk as viewed from the controller cache perspective. In the
live statistics, performance numbers are obtained by accounting for when data is written from cache
to disk or is read from disk to cache.
Historical data is obtained by using the summation of the disk statistics for the disks in the vdisk. The
historical vdisk data shows transfers to and from the disks in the vdisk that include the overhead of
any RAID transfers as well as any host activity.
Because I/Os from the RAID engine are included, values for the historical data appear higher than
the numbers for the live data.
Min. role
monitor
Syntax
To show live statistics:
show vdisk-statistics
[
vdisks
]
To show historical statistics:
show vdisk-statistics
[all]
[count
number-of-data-samples
]
historical
[time-range "
date/time-range
"]
vdisk
Parameters
all
Optional. Specifies to show the full set of performance metrics. If this parameter is omitted, the
default set of performance metrics will be shown.
count
number-of-data-samples
Optional. Specifies the number of data samples to display, from 1 to 100. Each sample will be
shown as a separate row in the command output. If this parameter is omitted, 100 samples will be
shown. If you specify this parameter, do not specify the
time-range
parameter.
Summary of Contents for AssuredSAN 6004
Page 11: ...Document conventions and symbols 11 TIP Provides helpful hints and shortcuts...
Page 114: ...114 Alphabetical list of commands See also set cli parameters show protocols...
Page 139: ...show controller statistics 139 See also reset all statistics reset controller statistics...
Page 162: ...162 Alphabetical list of commands See also show power supplies...
