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* [9fans] disturbing disk access
@ 2010-10-02  9:36 Rudolf Sykora
  2010-10-02 12:20 ` erik quanstrom
  0 siblings, 1 reply; 6+ messages in thread
From: Rudolf Sykora @ 2010-10-02  9:36 UTC (permalink / raw)
  To: Fans of the OS Plan 9 from Bell Labs

Hello,

even when I 'do nothing' there is a disk access every cca 15 seconds
on my plan9 notebook.
Can anyone tell me why this happens? Can I find what causes it?

It's quite disturbing and perhaps unnecessary...

Thanks!
Ruda



^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [9fans] disturbing disk access
  2010-10-02  9:36 [9fans] disturbing disk access Rudolf Sykora
@ 2010-10-02 12:20 ` erik quanstrom
  2010-10-02 15:54   ` Rudolf Sykora
  0 siblings, 1 reply; 6+ messages in thread
From: erik quanstrom @ 2010-10-02 12:20 UTC (permalink / raw)
  To: 9fans

> even when I 'do nothing' there is a disk access every cca 15 seconds
> on my plan9 notebook.
> Can anyone tell me why this happens? Can I find what causes it?

you can start with
	grep '(#S|/dev/sd..)/' /proc/*/fd

but obviously, that's just going to give you fossil or venti.

you can try looking for programs that might be sleeping for 15
seconds at a time,

minooka;  g 'sleep\(15[^)][^)]' . | awk -F: '{if($1 != o)print; o = $1}'
./faces/plumb.c:119: 			sleep(15000);
./upas/fs/fs.c:1603: 	sleep(15*1000);
./upas/pop3/pop3.c:710: 		sleep(15*1000);
./upas/imap4d/imap4d.c:858: 				sleep(15*1000);

if one of these is the culprit, it may be that your fs is writing
atimes to disk every 15 seconds.

> It's quite disturbing and perhaps unnecessary...

if the wild guess above is correct, you can either
- not run these programs, or
- use kfs with atime turned off rather than your current
fs setup.

- erik



^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [9fans] disturbing disk access
  2010-10-02 12:20 ` erik quanstrom
@ 2010-10-02 15:54   ` Rudolf Sykora
  2010-10-02 16:03     ` erik quanstrom
  0 siblings, 1 reply; 6+ messages in thread
From: Rudolf Sykora @ 2010-10-02 15:54 UTC (permalink / raw)
  To: Fans of the OS Plan 9 from Bell Labs

> you can start with
>        grep '(#S|/dev/sd..)/' /proc/*/fd
>

this gives me /dev/sdC0/^(fossil arenas isect) all many times

> minooka;  g 'sleep\(15[^)][^)]' . | awk -F: '{if($1 != o)print; o = $1}'

where do you run this so that you obtain the following? My 'g', as far
as I know, doesn't walk through directories... (???)

> ./faces/plumb.c:119:                    sleep(15000);
> ./upas/fs/fs.c:1603:    sleep(15*1000);
> ./upas/pop3/pop3.c:710:                 sleep(15*1000);
> ./upas/imap4d/imap4d.c:858:                             sleep(15*1000);

> if the wild guess above is correct, you can either
> - not run these programs, or
> - use kfs with atime turned off rather than your current
> fs setup.

Thanks
Ruda



^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [9fans] disturbing disk access
  2010-10-02 15:54   ` Rudolf Sykora
@ 2010-10-02 16:03     ` erik quanstrom
  2010-10-02 16:31       ` Rudolf Sykora
  0 siblings, 1 reply; 6+ messages in thread
From: erik quanstrom @ 2010-10-02 16:03 UTC (permalink / raw)
  To: 9fans

> this gives me /dev/sdC0/^(fossil arenas isect) all many times

so it could be atime access.  try halting all the programs
previously listed and seeing if that doesn't stop disk
activity.

> where do you run this so that you obtain the following? My 'g', as far
> as I know, doesn't walk through directories... (???)

contrib quanstro/g.  the idea was shamelessly stolen from russ,
with the additional twist that directories passed as arguments
are recursively searched.  thus "g pattern" in /sys/src/cmd searches
only single-file commands; while "g pattern ." searches all commands.

- erik



^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [9fans] disturbing disk access
  2010-10-02 16:03     ` erik quanstrom
@ 2010-10-02 16:31       ` Rudolf Sykora
  2010-10-02 16:39         ` erik quanstrom
  0 siblings, 1 reply; 6+ messages in thread
From: Rudolf Sykora @ 2010-10-02 16:31 UTC (permalink / raw)
  To: Fans of the OS Plan 9 from Bell Labs

> so it could be atime access.  try halting all the programs
> previously listed and seeing if that doesn't stop disk
> activity.

ok
I don't know exactly what I killed, but killing what showed as 'fs' by
'ps' helped.
No more disc operation every 15 seconds any more...
Thanks!
Ruda



^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [9fans] disturbing disk access
  2010-10-02 16:31       ` Rudolf Sykora
@ 2010-10-02 16:39         ` erik quanstrom
  0 siblings, 0 replies; 6+ messages in thread
From: erik quanstrom @ 2010-10-02 16:39 UTC (permalink / raw)
  To: 9fans

> I don't know exactly what I killed, but killing what showed as 'fs' by
> 'ps' helped.
> No more disc operation every 15 seconds any more...
> Thanks!

that's upas/fs.

- erik



^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2010-10-02 16:39 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2010-10-02  9:36 [9fans] disturbing disk access Rudolf Sykora
2010-10-02 12:20 ` erik quanstrom
2010-10-02 15:54   ` Rudolf Sykora
2010-10-02 16:03     ` erik quanstrom
2010-10-02 16:31       ` Rudolf Sykora
2010-10-02 16:39         ` erik quanstrom

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