[Debian-eeepc-devel] Idea about partitioning on 901

[Martin Weis]

Hello Ernesto!

Ernesto Domato schrieb:
> Well, I'd decided to reinstall my Eee 901 because the first time, I'd
> used LVM to join the two internal SSD. The problem that I see with
> this is that because of the slow write performance on the 16Gb disc,
> sometimes the machines hangs for several seconds waiting for something
> to finish. Maybe this is not related to LVM and the second disc, but
> after reading the wiki article about the problem with Mozilla
> (http://wiki.debian.org/DebianEeePC/TipsAndTricks#SpeedupsluggishIceweasel.2BAC8-Firefox3)
> I thought that maybe some changes on the partitioning may help to the
> situation.

My guess is, that long access times (on SSDs they can be up to 750 ms)
lead to the delays. Same here with a debian on second SSD, sometimes it
takes minutes to start an application.

> So, this is what I was thinking and will like to know your feedback:
> 
> The 4Gb disc is the fastest at writing, so my idea is to create 2
> partitions. The first one will be 1Gb for /var since the system writes
> often here (for example, on /var/log) and the second will  3Gb for
> /home (I'll explain why this soon).

Maybe it would be good to reduce writing anyway, here are some tips of a
colleague (that I did not apply here yet):

- mount filesystem with "noatime"
- delay automatic sync
  /etc/sysctl.conf:
  	vm.dirty_writeback_centisecs = 1500
- tune syslogd:
  level 1:
  	do not sync each line:
		in /etc/syslog.conf
			target    /log/file
			->
			target    -/log/file
  level 2:
    do not log unnessesary things,
	he keeps in /etc/syslog.conf:
		kern.*		-/var/log/kern.log
		*.emerg		-/var/log/syslog.log
  level 3:
	do not write to a file, but to a named pipe:
		kern.*		|/dev/xconsole
		*.emerg		|/dev/xconsole
	read with:
		xconsole -file /dev/xconsole

- delete /var/log/wtmp, /var/log/btmp and remove the lines from
/etc/logrotate.conf.
- mount /tmp, /var/run, Firefox-Cache in $HOME to tmpfs or Ramdisk.

Also there is a wiki entry about read only root:
http://wiki.debian.org/ReadonlyRoot

> Then, on the 16Gb create two more partitions. The first will be 4Gb
> for / and the second one will be 12Gb for /var/local/homes_data
> 
> So, the idea of the 3Gb partition mounted on /home is to be used for
> all the dot-directory (the hidden ones) that use to be updated often
> by the programs you use to keep configuration changes and things like
> that (see the Mozilla problem that I point before). The rest (for
> example the Desktop directory) is linked to
> /var/local/homes_data/$USER for storage purpose.

sounds reasonable...

-- 
Martin

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 252 bytes
Desc: OpenPGP digital signature
URL: <http://lists.alioth.debian.org/pipermail/debian-eeepc-devel/attachments/20090617/f63c2ea2/attachment.pgp>