NFSIOSTAT(1)		      Linux User's Manual		  NFSIOSTAT(1)



NAME
       nfsiostat  -  Report  input/output  statistics  for network filesystems
       (NFS).

SYNOPSIS
       nfsiostat [ -h ] [ -k | -m ] [ -t ] [ -V ] [ interval [ count ] ]

DESCRIPTION
       The nfsiostat command displays statistics about read and	 write	opera-
       tions 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  command  generates
       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  command	takes  into  account the following environment
       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 command  will  use	the  ISO  8601	format
	      (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 to work.


FILE
       /proc/self/mountstats contains statistics for network filesystems.

AUTHORS
       Written by Ivana Varekova (varekova <at> redhat.com)

       Maintained by Sebastien Godard (sysstat <at> orange.fr)

SEE ALSO
       sar(1), pidstat(1), mpstat(1), vmstat(8), iostat(1), cifsiostat(1)

       http://pagesperso-orange.fr/sebastien.godard/



Linux				 JANUARY 2011			  NFSIOSTAT(1)