vxstat(1M) VxVM 3.5 vxstat(1M)
1 Jun 2002
NAME
vxstat  VERITAS Volume Manager statistics management utility
SYNOPSIS
vxstat [dpsv ] [f fields ] [g diskgroup] [i interval [ c count ]]
[n node [,node...]] [r ] [object...]
DESCRIPTION
The vxstat utility prints and resets statistics information on one or
more volumes, plexes, subdisks, or disks.
The vxstat utility reads statistics from the volume device files in
the directory /dev/vx/rdsk and prints them to standard output. These
statistics represent volume, plex, subdisk, and disk activity since
boot time. If no object operands are given, then statistics from all
volumes in the configuration database are reported. object can be the
name of a volume, plex, subdisk, or disk.
In a VERITAS Volume Manager (VxVM) cluster environment, vxstat gathers
the requested statistics from all nodes in the cluster, and reports
the aggregate totals. You can specify a node list to indicate a subset
of nodes from which to gather statistics.
OPTIONS
c count Stop after printing interval statistics count times.
d Display statistics for disks on which the object specified
on the command line is fully or partially located.
f fields Select the display of statistics collected. The following
options are available:
0  O Statistics for the VOL_R5_ZERO operation. Each
operation represents one call to the VOL_R5_ZERO
ioctl. The number of blocks is based on the
number of zeroed blocks written to the array. The
average time is the time taken to complete the
entire ioctl operation.
a Statistics on atomic copies performed (has meaning
only for mirrored volumes). Displays the number
of operations, number of blocks, and the average
time spent per operation.
b Displays the statistics on readwriteback mirror
consistency recovery operations (has meaning only
for mirrored volumes). Displays three fields: the
number of readwriteback operations, the number of
blocks involved in readwriteback operations, and
the average time for completing a readwriteback
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1 Jun 2002
operation. While in recovery mode, most read
operations to a mirrored volume invoke read
writeback consistency recovery.
c Statistics on corrected (fixed) read operations
(has meaning only for mirrored or RAID5 volumes).
Displays the number of fixed read and write
operations.
Note: Currently, only read operations are ever
corrected, so the number of fixed writes will
always be zero.
C Statistics for the VOL_R5_RECOVER operation. Each
operation count represents one call to the
VOL_R5_RECOVER ioctl. The number of blocks
represents the resulting number of blocks that
were written to the missing column region as part
of the data recovery. The read operations are not
counted towards the total.
f Displays the number of failed read and write
operations.
F Statistics for fullstripe writes on a RAID5
volume. The number of operations represents the
number of write operations within a stripe that
were conducted as a fullstripe write
optimization. Fullstripe writes represent
considerably less overhead than readmodifywrites
in terms of overall I/O time, latency and CPU
overhead. The total number of blocks represents
the total size of the written data and the average
time is the time taken for a fullstripe write
operation. Since the I/O may be larger then a
single stripe, more than one stripe operation may
be seen for a single logical I/O request.
M Readmodifywrite statistics. Each operation
represents a readmodify write operation performed
within a stripe. I/O crossing a stripe boundary
will be represented by more than a single read
modify write operation. The number of blocks
counted represents only the size of the requested
write. The read portion of the I/O can be
derived.
R Reconstruct read operations. Each operation is a
separate reconstruct read operation. A single
stripe read or write operation can lead to
numerous reconstruct read operations since each
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reconstruction takes place at the subdisk level.
A detached column can consist of several subdisks
each of which will lead to a reconstruct read
operation.
s Statistics on read and write operations. Displays
six fields: the number of read operations, the
number of write operations, the number of blocks
read, the number of blocks written, the average
time spent on read operations in the interval, and
the average time spent on write operations in the
interval. These statistics are displayed as the
default output format.
S Statistics for the VOL_R5_RESYNC operation. Each
operation count represents one call to the
VOL_R5_RESYNC ioctl. The number of blocks
represents the resulting number of blocks that
were written to the parity regions as part of the
resynchronization of parity. The read operations
are not counted towards the total.
v Statistics on verified reads and writes (has
meaning only for mirrored volumes). Displays six
fields: the number of verified read operations,
the number of verified write operations, the
number of blocks read, the number of blocks
written, the average time spent on verified read
operations in the interval, and the average time
spent on verified write operations in the
interval.
V Statistics for the VOL_R5_VERIFY operation. Each
operation count represents one call to the
VOL_R5_VERIFY ioctl. The number of blocks
represents the resulting number of blocks that
were read as part of the RAID5 stripes
consistency verification.
W Reconstruct write statistics. Each operation
counted is for a reconstruct write operation
performed as an optimization of a write operation
within a stripe. The number of blocks counted
represents the count of data blocks written not
including parity or read operations.
g diskgroup
Select records from the specified disk group. The diskgroup
option argument can be either a disk group name or disk
group ID.
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i interval
Print the change in volume statistics that occurs after
every interval seconds. The first interval is assumed to
encompass the entire previous history of objects.
Subsequent displays will show statistics with a zero value
if there has been no change since the previous interval.
n node[,node...]
Gathers and displays statistics for the nodes specified in
node, where node is a comma separated list of integer node
numbers.
p Display statistics for plexes on the object specified on the
command line. For subdisk objects, displays information
about a plex with which it is associated.
r Reset statistics instead of printing them. This option will
follow the same selection rules as printing for any type
selection arguments or for any named objects. If an
interval was specified on the command line, then the first
set of statistics will not be printed since they will have
been reset to zero. Subsequent activity will cause printing
of statistics as normal.
s Display statistics for subdisks on the objects specified on
the command line.
v Display statistics for volumes on the objects specified on
the command line. For an object that is a plex or a
subdisk, displays information about the volume with which
the object is associated. If an object supplied is a disk,
then any volumes that occupy any part of the disk will be
selected.
OUTPUT FORMAT
Summary statistics for each object are printed in oneline output
records, preceded by two header lines. The output line consists of
blankseparated fields for the object type, object name (standard),
and the fields requested by the f switch in the order they are
specified on the command line.
If the i interval option was supplied, then statistics will be
prefaced with a timestamp showing the current local time on the
system.
EXIT CODES
The vxstat utility exits with a nonzero status if the attempted
operation fails. A nonzero exit code is not a complete indicator of
the problems encountered, but rather denotes the first condition that
prevented further execution of the utility.
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1 Jun 2002
See vxintro(1M) for a list of standard exit codes.
EXAMPLES
To display statistics for all subdisks associated with all volumes,
use the command:
vxstat s
To display statistics for the plexes and subdisks of a volume named
blop, use the following:
vxstat ps blop
To reset all statistics for a disk group named foodg, type the
following command:
vxstat g foodg r
To display 5 sets of disk statistics at 10 second intervals, use the
following:
vxstat i 10 c 5 d
SEE ALSO
vxintro(1M), vxtrace(1M), vxtrace(7)
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