ureadahead does not fully utilize disk

[Ed Novak]

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%.

[Ken Sharp (kennybobs)]

"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