NFSIOSTAT-SYSSTAT(1) Linux User's Manual NFSIOSTAT-SYSSTAT(1)NAMEnfsiostat-sysstat (the nfsiostat command from the sysstat package) -
Report input/output statistics for network filesystems (NFS).
SYNOPSISnfsiostat-sysstat [ -h ] [ -k | -m ] [ -t ] [ -V ] [ interval [ count ]
]
DESCRIPTION
The nfsiostat-sysstat command displays statistics about read and write
operations on NFS filesystems.
The interval parameter specifies the amount of time in seconds between
each report. The first report contains statistics for the time since
system startup (boot). Each subsequent report contains statistics col‐
lected during the interval since the previous report. A report con‐
sists of an NFS header row followed by a line of statistics for each
network filesystem that is mounted. The count parameter can be speci‐
fied in conjunction with the interval parameter. If the count parameter
is specified, the value of count determines the number of reports gen‐
erated at interval seconds apart. If the interval parameter is speci‐
fied without the count parameter, the nfsiostat-sysstat command gener‐
ates reports continuously.
REPORT
The Network Filesystem (NFS) report provides statistics for each
mounted network filesystem. Transfer rates are shown in 1K blocks by
default, unless the environment variable POSIXLY_CORRECT is set, in
which case 512-byte blocks are used. The report shows the following
fields:
Filesystem:
This columns shows the hostname of the NFS server followed by a
colon and by the directory name where the network filesystem is
mounted.
rBlk_nor/s (rkB_nor/s, rMB_nor)
Indicate the number of blocks (kilobytes, megabytes) read by
applications via the read(2) system call interface. A block has
a size of 512 bytes.
wBlk_nor/s (wkB_nor/s, wMB_nor/s)
Indicate the number of blocks (kilobytes, megabytes) written by
applications via the write(2) system call interface.
rBlk_dir/s (rkB_dir/s, rMB_dir/s)
Indicate the number of blocks (kilobytes, megabytes) read from
files opened with the O_DIRECT flag.
wBlk_dir/s (wkB_dir/s, wMB_dir/s)
Indicate the number of blocks (kilobytes, megabytes) written to
files opened with the O_DIRECT flag.
rBlk_svr/s (rkB_svr/s, rMB_svr/s)
Indicate the number of blocks (kilobytes, megabytes) read from
the server by the NFS client via an NFS READ request.
wBlk_svr/s (wkB_svr/s, wMB_svr/s)
Indicate the number of blocks (kilobytes, megabytes) written to
the server by the NFS client via an NFS WRITE request.
ops/s
Indicate the number of operations that were issued to the
filesystem per second.
rops/s
Indicate the number of 'read' operations that were issued to the
filesystem per second.
wops/s
Indicate the number of 'write' operations that were issued to
the filesystem per second.
OPTIONS-h Make the NFS report easier to read by a human.
-k Display statistics in kilobytes per second.
-m Display statistics in megabytes per second.
-t Print the time for each report displayed. The timestamp format
may depend on the value of the S_TIME_FORMAT environment vari‐
able (see below).
-V Print version number then exit.
ENVIRONMENT
The nfsiostat-sysstat command takes into account the following environ‐
ment variables:
S_TIME_FORMAT
If this variable exists and its value is ISO then the current
locale will be ignored when printing the date in the report
header. The nfsiostat-sysstat command will use the ISO 8601 for‐
mat (YYYY-MM-DD) instead. The timestamp displayed with option
-t will also be compliant with ISO 8601 format.
POSIXLY_CORRECT
When this variable is set, transfer rates are shown in 512-byte
blocks instead of the default 1K blocks.
BUG
/proc filesystem must be mounted for nfsiostat-sysstat to work.
FILE
/proc/self/mountstats contains statistics for network filesystems.
WARNING
The nfsiostat command from the sysstat package (nfsiostat-sysstat) is
now obsolete and is no longer maintained. It will be removed in a
future sysstat version. Please use now the nfsiostat command from the
nfs-utils package.
AUTHOR
Written by Ivana Varekova (varekova <at> redhat.com)
SEE ALSOnfsiostat(8), sar(1), pidstat(1), mpstat(1), vmstat(8), iostat(1), cif‐
siostat(1)Linux JANUARY 2014 NFSIOSTAT-SYSSTAT(1)
