Power Management & RAID5 array

Scottland · 16 Sep 2006 at 11:54

Does anybody know, if I were running a (software) R5 array, if I could use power management safely in Windows2003?

What I want to be able to do, is shut off the hard drives when they're not being used, to save power. They won't be on and off all the time, it'll be more like over night, and during the day when I'm at work.

But, will sutting them down (i.e. going into standby) have an impact on the array?

daz · 16 Sep 2006 at 12:00

Running software RAID5 is a bad idea in general... performance will suffer greatly.

Going into standby shouldn't have an effect though.

Scottland · 16 Sep 2006 at 12:04

daz said:
Running software RAID5 is a bad idea in general... performance will suffer greatly.

Going into standby shouldn't have an effect though.

Performance in what respect?

goreblast · 17 Sep 2006 at 09:53

Well the CPU will have to calculate all the parity data. With a hardware Raid 5 card there is a XOR processor with (usually) onboard RAM to do all the calculations and therefore free up the processor and make the system faster.

Scottland · 17 Sep 2006 at 10:15

But if the system is going to be soley used as a file server, it shouldn't have much effect?

goreblast · 17 Sep 2006 at 10:56

The other advantage of a Raid 5 hardware card is that the array can be transferred into a different system. Your software array would be tied to that PC and that PC only I think.

NickK · 17 Sep 2006 at 13:43

Don't use powersave on the harddrives. RAID5 spreads the volume's parity data over the whole set of drives.

The only time when you could stop this from happening is if you unmounted the volume as the OS wouldn't see the volume anymore.

daz · 17 Sep 2006 at 19:56

Scottland said:
But if the system is going to be soley used as a file server, it shouldn't have much effect?

It will mean that files are served more slowly than they otherwise could be with a hardware card.