Arch Linux

imrehg

Member

From: London, UK

Registered: 2008-04-10

Posts: 108

Website

Arch on EeePC SD card - giant latencies - replace ext3 with what?

Hi!

I've been using Arch on an EeePC 8G installed on an SDHC card, on ext3. The problem is, that it has pretty bad latencies every few second when e.g. browsing. According to latencytop, the main problem is:

log_wait_commit journal_stop journal_force_commit

sometimes several seconds of latency and also

sync_page
sync_buffer

These are due to the filesystem, aren't they?

I was wondering, whether a different choice of filesystem instead of ext3 would be better, with less latency. I tried ext2 originally, since I read that journalling might not be good for the SD card, but then every startup was a pain, as for some reason the system forced a check. With ext3 it's a breeze to start. So Xfs, Jfs or something else would be better to reduce the latency and still keep the journalling goodness? Or maybe one of the flash filesystems like jffs2?

gothicknight

Member

From: Portugal

Registered: 2006-04-08

Posts: 219

Re: Arch on EeePC SD card - giant latencies - replace ext3 with what?

You shouldn't use journaling filesystems with flashcards, I would put at first, to find the reason to those fs checks.
But you could try add "elevator=noop" in your GRUB configuration file kernel line.

Bogart

Member

From: Madrid, Spain

Registered: 2005-06-22

Posts: 272

Re: Arch on EeePC SD card - giant latencies - replace ext3 with what?

Read this guide:

http://wiki.archlinux.org/index.php/Ins … sus_EEE_PC

Basically, use ext2 with noatime, no swap, disable any logging of messages (also for example on Pidgin or Kopete), minimize writes to disk (in Firefox you might want to disable the anti-fishing capabilities, as long as you're certain you don't need them, among other things), etc...