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zcav(1)                     General Commands Manual                    zcav(1)

       zcav - program to test raw hard drive throughput.

       zcav   [-b   block-size]  [-c  count]  [-u  uid-to-use:gid-to-use]  [-g
       gid-to-use] [-f] file-name

       This manual page documents briefly the zcav, program.

       Modern hard drives have a constant rotational speed  but  have  varying
       numbers  of  sectors per track (outside tracks are longer and have more
       sectors). This is referred to as Zoned Constant  Angular  Velocity  (or
       ZCAV).  The  outer  tracks will have a higher data transfer rate due to
       having more sectors per track, these tracks generally  have  the  lower
       track/sector numbers.

       This program tests the ZCAV performance of a hard drive, by reading the
       entire data on it a specified number of times. The file name  given  as
       the first parameter, it can be specified as -, for standard input. This
       file will be opened as read-only and in  usual  operation  it  will  be
       /dev/hdX  or /dev/ide/host0/busX/targetY/lun0/disc depending on whether
       you use devfs or not (NB operating systems other than Linux  will  have
       different device names).

       The  output  should  be able to be easily graphed with gnuplot which is
       what I use to view the results.

       -b     the size of the blocks to read from disk (default 100M).

       -c     the number of times to read the entire disk.

       -f     the file-name for the input data. This isn't needed on well con-
              figured  systems  that have a recent Glibc where you can specify
              the file name without the -f flag.

       -u     user-id to use.  When running as root specify the UID to run the
              tests  as,  it is not recommended to use root, so if you want to
              run as root use -u root.  Also if you want to specify the  group
              to run as then use the user:group format.  If you specify a user
              by name but no group then the primary group of that user will be
              chosen.   If  you specify a user by number and no group then the
              group will be nogroup.

       -g     group-id to use.  Same as using :group  for  the  -u  parameter,
              just  a different way to specify it for compatibility with other

       This program, it's manual page, and the Debian package were written  by
       Russell Coker <russellATcoker.au>.