[Bug 1201114] Re: ureadahead does not fully utilize disk

[Ken Sharp]

"I looked at bootchart, and ureadahead doesn't get full throughput

Even though ureadahead reads everything in one go, and is heavily
optimised to read everything in the actual order it's on the disk, it
still has to skip over the bits it doesn't need.

This "seek time" is the same performance penalty as finding data in the
first place.

The only way to avoid this is defragmenting your disk."
http://ubuntuforums.org/showthread.php?t=1434502

** Changed in: ureadahead (Ubuntu)
       Status: New => Invalid

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https://bugs.launchpad.net/bugs/1201114

Title:
  ureadahead does not fully utilize disk

Status in “ureadahead” package in Ubuntu:
  Invalid

Bug description:
  First of all, this is on a linux mint system.  It's mint 13 which is
  based on Ubuntu 12.04.  The manpage for ureadahead said to report bugs
  here so i am.

  The problem I'm experiencing is similar to:
  https://bugs.launchpad.net/ubuntu/+source/ureadahead/+bug/1074428
  however it is exacerbated by the fact that ureadahead does not fully
  utilize my disk!  I am only getting about 50% utilization.  Attached
  is a bootchart.png from my system.

  Also, any tips on getting my system to boot faster are greatly
  appreciated!

  uname -a
  Linux glass 3.2.0-49-generic #75-Ubuntu SMP Tue Jun 18 17:40:13 UTC 2013 i686 i686 i386 GNU/Linux

  cat /etc/issue
  Linux Mint 13 Maya

  apt-cache policy ureadahead
  ureadahead:
    Installed: 0.100.0-12
    Candidate: 0.100.0-12
    Version table:
   *** 0.100.0-12 0
          500 http://archive.ubuntu.com/ubuntu/ precise/main i386 Packages
          100 /var/lib/dpkg/status

  
  Just to be thorough, I expected ureadahead to get near 100% utilization (min of 80%, average of ~90%) when booting.  Instead I see utilization around 50%.

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