GENBACKUPDATA(1)					      GENBACKUPDATA(1)



NAME
       genbackupdata - generate backup test data

SYNOPSIS
       genbackupdata [options] directory

DESCRIPTION
       genbackupdata  generates  test  data  sets  for	performance testing of
       backup software.  It creates a directory tree filled with files of dif
       ferent  sizes.	The  total  size and the distribution of sizes between
       small and big are configurable.	The program can also modify an	exist
       ing  directory  tree  by creating new files, and deleting, renaming, or
       modifying existing files.  This can be used to generate test  data  for
       successive generations of backups.

       The  program  is  deterministic:  with a given set of parameters (and a
       given pre-existing directory tree), it always creates the same  output.
       This  way,  it  is  possible to reproduce backup tests exactly, without
       having to distribute the potentially very large test sets.

       The data set consists of plain files and directories.  Files are either
       small  text  files  or big binary files.  Text files contain the "lorem
       ipsum" stanza, binary files contain randomly  generated	byte  streams.
       The  percentage of file data that is small text or big binary files can
       be set, as can the sizes of the respective file types.

       Files and directories are named "fileXXXX" or "dirXXXX",  where	"XXXX"
       is  a  successive  integer, separate successions for files and directo
       ries.  There is an upper limit to how many files a directory  may  con
       tain.  After the file limit is reached, a new sub-directory is created.
       The first set of files go into the root directory of the test set.

       You have to give one of the options --create,  --delete,  --rename,  or
       --modify  for  the program to do anything.  You can, however, give more
       than one of them, if DIR already exists.  (Giving the same option  more
       than once means that only the last instance is counted.)  (DIR) is cre
       ated if it doesnt exist already.

OPTIONS
       When giving file sizes (SIZE below), the default unit is a  byte.   The
       suffixes  "K",  "M", "G", and "T" (upper or lower) can be used to refer
       to kibi-, mebi-, gibi-, and tebibytes, respectively (2 to the power  of
       10, 20, 30, or 40).

       When  giving  file counts (COUNT below), the same suffixes may be used,
       but then they will refer to kilo-, mega-, giga-, and tera- (10  to  the
       power of 3, 6, 9, or 12).

       When  referring	to a size or file count, when it makes sense to give a
       relative size, the suffix "%" may be used to indicate percentage.

       Numbers may be integer or floating point (using the  locales  floating
       point syntax).

       --seed=SEED
	      Set  the	(integer)  seed to the psuedo-random number generator.
	      Default: 0.

       --max-files=COUNT
	      Set the maximum number of files in a directory.  Default: 256.

       -p, --percentage-text-data=PERCENTAGE
	      Set the percentage of file data (not file count) in  newly  cre
	      ated  files  (not modified files) allocated to small text files.
	      Default: 10%.

       -t, --text-file-size=SIZE
	      Set the  size  of  text  files.	Cannot	be  a  relative  size.
	      Default: 10 KiB.

       -b, --binary-file-size=SIZE
	      Set  the	size  of  binary  files.   Cannot  be a relative size.
	      Default: 10 MiB.

       -c, --create=SIZE
	      Create SIZE amount of new files.	A relative  amount  refers  to
	      the  size  of  the  pre-existing	files.	 DIR  is created if it
	      doesnt exist already.  Default: 0.

       -d, --delete=COUNT
	      Remove COUNT pre-existing files.	A relative  amount  refers  to
	      the  number  of  pre-existing  files.   DIR  must exist already.
	      Default: 0.

       -r, --rename=COUNT
	      Rename COUNT pre-existing files to new names,  without  changing
	      the  contents.   A  relative amount refers to the number of pre-
	      existing files.  DIR must exist already.	Default: 0.

       -l, --link=COUNT
	      Create COUNT links to pre-existing files.

       -m, --modify=SIZE
	      Modify pre-existing files by appending to them.  The new data is
	      divided into text and binary data as for --create, but no regard
	      is given as to whether the file that receives the new data is  a
	      text  or binary file.  Files are picked by random among the pre-
	      existing ones, and the size is increased according to  the  per
	      centage  set  by --modify-percentage.  A relative SIZE refers to
	      the total size of pre-existing files.  DIR must  exist  already.
	      Default: 0.

       --modify-percentage=PERCENT
	      Set  the	number of percent each file is grown when using --mod
	      ify.  Note that zero size files are not grown (X% of 0 is always
	      0).  Default: 10%.

EXAMPLES
       Create data for the first generation of a backup:

	      genbackupdata --create=10G testdir

       Modify an existing set of backup data to create a new generation:

	      genbackupdata -c 5% -d 2% -m 5% -r 0.5% testdir

       The above command can be run for each new generation.



							      GENBACKUPDATA(1)