> Most messages on this forum have focused on optimizing performance,
> however I'm looking for suggestions in an effort to reduce power
> consumption on the 1.2TB RAID servers we run.
> The boxes are mostly used for archiving huge amounts of data and only
> see usage for a third of the day at most. They are setup with a 7500-8
> with 8 Maxtor 160GB drives plus IDE boot drive and CDROM. They are
> running RedHat Linux 7.3 with ReiserFS filesystem and Samba shared
> mounts.
> The plan is:
> * Enable power saving options in BIOS for on-board IDE bus and CPU
> * Does 3ware support powering down drives during period of inactivity?
You could use "hdparm -Sxxx /dev/hdx" to set the spin-down time outs.
-S242 would set the timeout to 1 hour. The man page says:
-S Set the standby (spindown) timeout for the drive.
This value is used by the drive to determine how
long to wait (with no disk activity) before turning
off the spindle motor to save power. Under such
circumstances, the drive may take as long as 30
seconds to respond to a subsequent disk access,
though most drives are much quicker. The encoding
of the timeout value is somewhat peculiar. A value
of zero means "off". Values from 1 to 240 specify
multiples of 5 seconds, for timeouts from 5 seconds
to 20 minutes. Values from 241 to 251 specify from
1 to 11 units of 30 minutes, for timeouts from 30
minutes to 5.5 hours. A value of 252 signifies a
timeout of 21 minutes, 253 sets a vendor-defined
timeout, and 255 is interpreted as 21 minutes plus
15 seconds.
This should work on most drives, including SCSI type.
Also, for the CPU, you can compile the kernel with the APM driver and
enable the "hlt" instruction. That will save power too.
If you have a newer type of system you can use the the S3 (STR)
power-save mode. STR, or Suspend To Ram, is quite efficient. I think
you should be down to a few Watts when the system is in STR mode. It
is quick to resume from.
- Anders
> Are there any other options? Obviously I could have the machines power
> down at night...the tricky thing is getting them to boot back at a
> specific time each day. I can't remember if the BIOS in those boxes
> have that option or not, I'll investigate.
> The shutdown would need to occur from Linux to make sure everything was
> shutdown cleanly.
> Any other suggestions? Saving ~ 60% on electricity charges is
> definately a win when you have several of these boxes running.
> Thanks,
> Ryan
