power saving..

I have a relatively large (11 drive) server that operates 24/7.

It really doesn't need to, though.  Use is sporadic at best; the purpose
is mostly archiving.

So what I'm wondering, is do we have auto-spin-down, power save features
available & STABLE?  This thing sucks down a lot of power, giving me a
bunch of heat in return :-)

On Mon, 25 Aug 2003, mjstumpf wrote:

I have a relatively large (11 drive) server that operates 24/7.

It really doesn't need to, though.  Use is sporadic at best; the purpose
is mostly archiving.

So what I'm wondering, is do we have auto-spin-down, power save features
available & STABLE?  This thing sucks down a lot of power, giving me a
bunch of heat in return :-)

The problem isn't the spin-down, but the spin-up.  When an I/O occurs, the
delay for the disks to spin up would be likely to cause the RAID card (if
you use one) to generate a timeout.  If you don't use a RAID card, it
might work (and it might not).

These disks probably draw around 10W each at idle.  This is a 110W load in
your system.  All things considered, I'd be more likely to want to put the
CPU into sleep mode.  This would probably save 60-80W per CPU (figure 80%
efficiency on the voltage conversion), with some small additional power
savings from the NorthBridge and memory.

If the power savings (or heat output) is REALLY important, you can leave
the entire system off, except when you need it.  This may decrease the
long-term reliability, especially of the power supply.

				Peter Ashford

On Mon, 25 Aug 2003, mjstumpf wrote:

I have a relatively large (11 drive) server that operates 24/7.

It really doesn't need to, though.  Use is sporadic at best; the purpose
is mostly archiving.

So what I'm wondering, is do we have auto-spin-down, power save features
available & STABLE?  This thing sucks down a lot of power, giving me a
bunch of heat in return :-)

I'd be concerned about premature disk failure from cycling the drives up
and down, which could end up being more expensive than your power bill.

Mike

On Mon, 25 Aug 2003, mjstumpf wrote:

I have a relatively large (11 drive) server that operates 24/7.

It really doesn't need to, though.  Use is sporadic at best; the purpose
is mostly archiving.

So what I'm wondering, is do we have auto-spin-down, power save features
available & STABLE?  This thing sucks down a lot of power, giving me a
bunch of heat in return :-)

Sorry for a late reply, but I've been on holiday...

I asked something like this a while back and got a positive reply. I've
been using "noflushd" on a small server/firewall for some time with good
results.  It's only a 2-disk RADI-1 system and what I've found is that one
drive is spun-down nearly all of the time, and the other is spun down most
of the time. It onl seems to spin up one disk when it need to read
something thats not in memory. Spin-up time is about 8 seconds (these are
old drives)  and it works very well and runs very cool and mostly quiet.

Gordon
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On Mon, 25 Aug 2003, mjstumpf wrote:

I have a relatively large (11 drive) server that operates 24/7.

It really doesn't need to, though.  Use is sporadic at best; the purpose
is mostly archiving.

So what I'm wondering, is do we have auto-spin-down, power save features
available & STABLE?  This thing sucks down a lot of power, giving me a
bunch of heat in return :-)

Sorry for a late reply, but I've been on holiday...

I asked something like this a while back and got a positive reply. I've
been using "noflushd" on a small server/firewall for some time with good
results.  It's only a 2-disk RADI-1 system and what I've found is that one
drive is spun-down nearly all of the time, and the other is spun down most
of the time. It onl seems to spin up one disk when it need to read
something thats not in memory. Spin-up time is about 8 seconds (these are
old drives)  and it works very well and runs very cool and mostly quiet.

Gordon