Spinning down drives

Richard Gooch (rgooch@atnf.CSIRO.AU)
Sat, 5 Jul 1997 02:20:21 +1000


I wrote:
> Hi, all. I've trawled the configuration files for 2.0.30 and 2.1.42
> and can't find that NO_ATIME patch I remember hearing about when
> 2.0.30 came out. Could some kind soul tell me where it is?
> I've got a laptop with 2.0.30 and I've set the HD spindown timeout to
> 40 seconds, but something causes it to spin up every minute or so. I
> presume that's the bdflush daemon. This is on a totally idle system,
> so it doesn't quite make sense: I would have thought once buffers are
> flushed, there is no point doing it again... Even killing off all my
> daemons (even syslogd) doesn't help.

I tried mounting filesystems with -o noatime and that didn't help. I
then ran update (bdflush) with -f 300 to set the timeout to 5
minutes. That worked. It still seems odd that bdflush (1, NULL) will
write to the disc if *no process has written to the disc since the
last call to bdflush*. Doesn't the kernel properly tag all buffers as
clean once bdflush is done?

On another note, I set my HD spindown time to 30 seconds on my main
machine (not a laptop) earlier today, and late tonight the drive
stopped responding! I got drive not ready errors, and when I rebooted
a few times, things got progressively worse, first making unpleasant
noises and now the drive ID string appears to be corrupted (Linux
prints some characters which would be fine for playing cards, but not
for properly identifying the drive). The BIOS doesn't even see it at
all! I could possibly imagine that spining a drive up and down could
cause it to fail to spin up properly, possibly even giving media
errors, but why the drive ID string (which is presumably in firmware)
would be corrupted is a mystery. Has anyone ever seen anything quite
like this? The drive is a Maxtor 7425AV (420 MByte IDE), purchassed
about 2.5 years ago.

Regards,

Richard....