mke2fs time speedup
===================
2009-05-01
Junichi Uekawa


Background
==========

dd / mke2fs sequence takes around 7 seconds on my system (core2duo
macbook). This is ran every time for create / update and build, which
means it can be optimized.  There are other parts, like kernel booting
time and apt install time and dpkg configuration time that are taking
majority of time (e.g. 2 minutes), and they will need to be looked at
for individual cases, but this looks like a clear win on all cases.



Plan
====

create_ext3_block_device currently creates a sparse file, and then
runs mke2fs and tune2fs on the resulting file.  This can be modified
so that a ext3 block device creater will create an empty file for the
first time, and then reusing it with a copy.

Initial measurement
===================

*TODO* Say that copying a 10G sparse file is faster than rerunning mke2fs


Final measurement
=================

*TODO* Actual results