Saturday 5 April 2008

EEE alternate OS installation plan

Constraints:
4G SSD
No optical drive (for install)

Requirements:
Should boot similar speed to default OS (10-15s on 630Mhz Celeron)
Reasonable wireless configuration tools

== Filesystem ==

Apparently reiserfs saves almost 200M in filesystem overhead. Plus it should store small files more compactly... but my calculations suggest journaling may be a bad idea, as confirmed by Asus choice to avoid it (mounting as ext2):

Maximum write b/w: 10Mb/s
Maximum reiser journal size: 127M (32749*4096)
SSD Write cycles: 100_000

Wear leveling will have very little effect. Typically wear leveling occurs in zones of around 4mb, and I assume this is contiguous (and so is the journal).

Now we should halve the bandwidth, since journal writes are accompanied by normal writes.

100_000 / (5Mb/s / 127M) = 100_000 * 25.4s = 2.54 mega-seconds, = 29.4 days.

This is absolute worst case - reiserfs only journals metadata, and it's not clear why one would generate 5Mb/s continous metadata writes without any data writes. But it looks better avoided. ext2 for me.

== Boot speed ==

Looks like Puppy linux might be good.
Alternatively, hibernation. Use swap file for flexibility (can resize). uswsusp can do compression for even more speed.