Thanks for your exceedingly rapid reply...
>> I am using linux 2.4.21 with xfs 1.3 on debian-unstable. Since I
>> upgraded from 2.4.18-xfs-1.1, my xfs partitions have been showing
>> pulses of activity every five seconds, I think because of xfssyncd.
>> The hard drive physically seeks every five seconds too.
>>
>> I have reviewed this mailing list and elsewhere for clues, but can't
>> work out either:
>> a) whether this behaviour is normal, or
>> b) how to change the interval.
>
> A sysctl variable controls this: /proc/sys/fs/xfs/sync_interval
Ok I hadn't realised that's where it lived. Mine's set to "3000". Does
this value rule out the diagnosis I've made?
> >>From Documentation/filesystems/xfs.txt...
>
> fs.xfs.sync_interval (Min: HZ Default: 30*HZ Max: 60*HZ)
> The interval at which the xfssyncd thread for xfs filesystems
> flushes metadata out to disk. This thread will flush log
> activity out, and do some processing on unlinked inodes
>
> What makes you suspect xfssyncd? It could also be some arbitrary
> process deciding to write something out every few seconds of course.
The reason I suspect xfssyncd is because it happens simultaneously on
all of one drive's xfs partitions together (ie /{,usr,var,home}), and
not on its non-xfs partitions. Additionally, this behaviour is new since
I upgraded to xfs 1.3.
It doesn't actually seem to be happening on another drive which has a
mounted xfs partition. Some other possibly relevant settings:
$ cat /proc/sys/vm/bdflush
30 500 0 0 500 3000 60 20 0
^ interval in 1/100s between kupdate
flushes -- could this be my problem?
$ cat /proc/sys/vm/kswapd
512 32 8
I guess I feel a bit out of my depth...
Jeremy
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