On the subject of noisy drives...
One thing that I have had on my Linux wish list for some time
is the ability to make use of the 'spin up/down' commands supported
by all SCSI drives that I know of. Does anyone know of any work
being done on that?
It would probably be useful on laptops with IDE drives as well,
where conserving battery life is important.
What is needed is to keep background processing to a minimum and
disk accesses confined to short bursts when the disk is spun down,
so that the drive is not continuously spun up and down. Disk caching
needs to be aggressive and the cache flushed to disk only when absolutely
necessary if a drive has been spun down.
In my preferred installation configuration I keep all filesystems
mounted read-only except for /home and /var, which is good both
for security and for simplifying backups. If /var were on, for
instance, a ram disk backed onto non-volatile storage which was
only updated once per day, or when interactive usage caused the
drive to spin up for some other reason, noise and power consumption
could be minimised on an idle system at the risk of occasionally
losing some logs in the event of a crash. Or perhaps a CF or other
solid state non-volatile storage could be used to store changes
for a journaled /var filesystem.
So assuming a fast SCSI drive could be spun down after, say, 30 minutes
of inactivity, and spun up automatically on demand, what are all the
things that would cause accesses on an idle (no interactive users or
applications) system?
What springs to mind is
cron jobs
should cron know about spun down disks, perhaps having with
a flag in crontab for entries that 'can wait' till next disk
spin-up
swapping/paging
clearing long term idle tasks from memory should wait till the
memory is actually needed if the disk is spun down
mail receipt?
fetchmail could be postponed if the drive is spun down...
SMPT mail delivery is trickier..
web servers...
a tricky problem is you are running a popular one..
what else?
I suppose the easy solution is to have a modest, low power, quiet IDE
system disk, with large SCSI screamer for a work filesystem that can
be unmounted and spun down when not in use. But it would be nice to
have it work automatically without an unmount or explicit spin up/down
commands.
Any thoughts?
Regards,
DigbyT
> On 17:34 Tue 29 Mar , daniel wrote:
> > I buy a new computer every 5 years or so. My current machine is an
> > Athlon800
> > and it continues to perform well because I was careful about my purchasing
> > back in 2000 and I'd like to repeat that this time around.
> >
> > To that end, I'm looking for suggestions from the lot of you with regard to
> > what kind of hardware I can/should get for my new shiny desktop machine.
>
> Some good suggestions in this thread. You'll find a nicely organized
> set of suggestions for systems of various price levels at:
>
> http://hardwareguys.com/picks/picks.html
>
> I've built based on their suggestions, with no prior experience at it,
> and had great success.
>
> The only thing they have missed, IMHO, are Western Digital's SATA
> drives. I have two of their 10,000 rpm Raptors running on a RAID0, my
> machine screams. These are Western Digital's effort to break into the
> commercial, i.e., scsi, market, and are, by all reports, rugged and
> reliable.
>
> The only real problems with scsi are that they tend to be LOUD, and
> they are priced for the commercial market, i.e., expensive.
>
> Bill Roberts
--
Digby R. S. Tarvin [EMAIL PROTECTED]
http://www.digbyt.com
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