[kwlug-disc] First observations on Lucid Lynx

[Chris Irwin]

On Mon, May 3, 2010 at 14:51, Richard Weait <richard at weait.com> wrote:
> On Mon, May 3, 2010 at 12:42 PM, Chris Irwin <chris at chrisirwin.ca> wrote:
>> I just received my SSD ("like, OMG! JUST NOW!!1"), so I'll be tweaking
>> a few things tonight (to avoid syncing my large media).
>
> Sweet.  I can recommend a nice torture test for it.  It involves lots
> of geographic data.
>
> noatime, seems like a nice addition to fstab for your ssd.  Just
> sayin' is all.

I've been a fan of 'relatime', which I believe is default now (at
least in Ubuntu). I was going to say how it only updates atime if it
was > 24 hours ago, but decided "Why not back this up with a link".
Turns out I am wrong. It turns out relatime updates atime only if
mtime or ctime is newer. Also, it turns out that the only thing that
really wants atimes is mutt using it to see if there is new mail in a
spool file (modified after last access). I don't use mutt or
spoolfiles (maidir ftw), and apparently that behaviour can be changed
anyway. So relatime sounds like a kernel-level workaround to preserve
the behaviour of one specific userspace program.

Furthermore, you can't get much more authoritative than Linus
Torvalds, Ingo Molnar, and Andrew Morton talking about how awesome
"noatime,nodiratime" is.

http://kerneltrap.org/node/14148

And here is an article from Ted "Mr. Filesystem" Tso talking about
noticeable benefits of noatime.

http://thunk.org/tytso/blog/2009/03/01/ssds-journaling-and-noatimerelatime/

So there you go. I'll set my fstab to noatime,nodiratime before I move
it over. Learn something every day.

-- 
Chris Irwin
<chris at chrisirwin.ca>