NAME

       disk-filltest - Simple Tool to Detect Bad Disks by Filling with Random Data

SYNOPSIS

       disk-filltest [-C dir] [-f files] [-N] [-r] [-R repeats] [-s seed] [-S size] [-u] [-U]

DESCRIPTION

       disk-filltest  The number of hard disk produced in the last five years is huge. Of course,
       this is the same number of hard disks that will most probably fail in the next five years,
       possibly with catastrophic consequences for the particular user or business.

       The  simple  tool  disk-filltest  can  help, together with S.M.A.R.T. monitoring, to check
       disks periodically and thus be forewarned about coming failures.  The  function  of  disk-
       filltest is simple:

       •  Write files random-######## to the current directory until the disk is full.

       •  Read the files again and verify the pseudo-random sequence written.

       •  Any write or read error will be reported, either by the operating system or by checking
          the pseudo-random sequence.

       •  Optionally, delete the random files after a successful run.

       The method is simple and effective, however, it of course does not verify other  files  on
       the  disk.  That  is a different task, which can be solved efficiently, for example, using
       digup (a Digest Updating Tool) (https://panthema.net/2009/digup/).

       Another useful side-function of disk-filltest is to measure read/write speed while filling
       the disk. Slow speeds may also indicate a future failure, or just bad disk controlling.

       See https://panthema.net/2013/disk-filltest/ for more information.

OPTIONS

       -C dir Change into given directory before starting work.

       -f files
              Only write this number of 1 GiB sized files.

       -N     Skip verification of files, e.g. for wiping a disk.

       -r     Only verify existing data files with given random seed.

       -R repeat
              Repeat  fill/test/wipe steps given number of times.  The random seed is not changed
              between repetitions.

       -s seed
              Use random seed to write or verify data files.

       -S size
              Size of each random file in MiB (default: 1024).

       -u     Remove files after successful test.

       -U     Immediately remove files, write and verify via file handles.

AUTHORS

       Written by Timo Bingmann

SEE ALSO

       dd(1), digup(1), fio(1)

                                            2019-10-21                           DISK-FILLTEST(1)