[9fans] disturbing disk access

[Rudolf Sykora]

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

Re: [9fans] disturbing disk access

[erik quanstrom]

 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

Re: [9fans] disturbing disk access

[Rudolf Sykora]

 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

Re: [9fans] disturbing disk access

[erik quanstrom]

 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

Re: [9fans] disturbing disk access

[erik quanstrom]

 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