NAME
vxstat - 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 stan-
dard output. These statistics represent volume, plex, sub-
disk, 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 Volume Manager 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 par-
tially located.
-f fields Select the display of statistics collected. The
following options are available:
0 | O Statistics for the VOL_R5_ZERO opera-
tion. 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 read-
writeback mirror consistency recovery
operations (has meaning only for mir-
rored volumes). Displays three fields:
the number of read-writeback operations,
the number of blocks involved in read-
writeback operations, and the average
time for completing a read-writeback
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 mir-
rored or RAID-5 volumes). Displays the
number of fixed read and write opera-
tions.
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 opera-
tion. 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 full-stripe writes on a
RAID-5 volume. The number of operations
represents the number of write opera-
tions within a stripe that were con-
ducted as a full-stripe write optimiza-
tion. Full-stripe writes represent con-
siderably less overhead than read-
modify-writes 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
full-stripe 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 Read-modify-write statistics. Each
operation represents a read-modify 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 por-
tion 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
reconstruction takes place at the sub-
disk level. A detached column can con-
sist of several subdisks each of which
will lead to a reconstruct read opera-
tion.
s Statistics on read and write operations.
Displays six fields: the number of read
operations, the number of write opera-
tions, 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 opera-
tion. 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 ver-
ified read operations, the number of
verified write operations, the number of
blocks read, the number of blocks writ-
ten, 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 opera-
tion. 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 RAID-5 stripes con-
sistency verification.
W Reconstruct write statistics. Each
operation counted is for a reconstruct
write operation performed as an optimi-
zation 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.
-i interval
Print the change in volume statistics that occurs
after every interval seconds. The first interval
is assumed to encompass the entire previous his-
tory 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 speci-
fied 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 statis-
tics 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 one-line
output records, preceded by two header lines. The output
line consists of blank-separated 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 time-stamp 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. 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)