NAME

       ureadahead - Read files in advance during boot

SYNOPSIS

       ureadahead [OPTIONS]...  [PACK]

DESCRIPTION

       ureadahead  (über-readahead)  is  used  during boot to read files in advance of when they are needed such
       that they are already in the page cache, improving boot performance.

       When started without any arguments, it checks for  the  existance  and  age  of  the  default  pack  file
       /var/lib/ureadahead/pack,  and if not present or older than a month, will discard it and retrace the boot
       sequence.  The pack will then contain information about the files opened during boot, and the blocks that
       were in memory at the completion of the boot.

       If the file exists and is newer than a month old, or an alternate PACK path is given on the command-line,
       the files listed in the pack are opened and the blocks read into the page cache  using  the  readahead(2)
       system call.

       Pack  files  are  automatically  optimised  for Solid-State Disks or rotational Hard Drives, depending on
       which you have.

OPTIONS

       --verbose
              May be used to report on ureadahead's operation.  In particular, this causes information about the
              size of the pack file to be output when reading and a complete dump of the contents  of  the  pack
              file after tracing.

       --daemon
              Places  ureadahead  into the background once the pack file has been read, or once tracing has been
              enabled.

              This is ignored when reading on rotational hard  drives,  since  it's  important  for  performance
              reasons not to contend with other processes for I/O.

       --force-trace
              Discards all pack files and forces re-tracing.

       --timeout=SECONDS
              Normally  when  tracing,  ureadahead  will  wait  for  a  TERM or INT signal before concluding and
              generating the pack file.  This option instead sets a timeout after which tracing is terminated.

       --dump Dump the contents of the pack file to standard output in a pretty format, does not trace  or  read
              the contents into memory.

       --sort=SORT
              Used with --dump to sort the output.

              The  default  is open, which is the order that the files will be opened.  path sorts by path name,
              disk sorts by on-disk location, and size sorts by the amount of data that will be  read  for  that
              file.

OTHER MOUNT POINTS

       PACK  need not be the filename of a pack, instead it may be the name of a mount point (or indeed any non-
       file within the filesystem), in which case the pack  for  that  device  is  read  instead.   This  allows
       ureadahead to be called in the style ureadahead /usr for filesystems split across multiple devices.

       Pack   files   for  these  other  devices  are  also  stored  under  /var/lib/ureadahead  and  are  named
       mountpoint.pack

       When tracing, these will be automatically generated.

FILES

       /var/lib/ureadahead/pack

AUTHOR

       Written by Scott James Remnant <scott@netsplit.com>

BUGS

       Report bugs at <https://launchpad.net/ubuntu/+source/ureadahead/+bugs>

COPYRIGHT

       Copyright © 2009 Canonical Ltd.

       This is free software; see the source for copying  conditions.   There  is  NO  warranty;  not  even  for
       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

SEE ALSO

       readahead(2)

ureadahead                                         2009-09-29                                      ureadahead(8)