[mythtv-users] Using spindown with SCSI RAID5?

[George Mari]

> 2008/6/25 George Mari <george_mythusers at mari1938.org>:
> 
>> Anyone out there had any success with spinning down SCSI disks in a
>> software RAID5 array for power saving?
>>
>> I tried to spin down one of my 4 disks in a RAID5 array, using the command:
>>
>> sdparm --command=stop /dev/sdi
>>
>> This spun the drive down (good), but it also kicked it out of the array.
>>  (bad)
>>
>> What I'm trying to do is just have it power down somehow after a certain
>> time being idle, and then just spin up again when accessed without
>> breaking the  but it seems that SCSI drives don't have all the power
>> management options that PATA or SATA drives do.  (Or maybe just my
>> particular SCSI drives don't have these features...)
>>
>> I'd love to hear from anyone with specific experience with trying to do
>> this with SCSI drives - thanks.
>> _______________________________________________
Silvestro Roberto wrote:
 > I think you can spin down only spare disks in the array!
 >

Well, I have read that the spare disks for a RAID5 or RAID6 can be spun 
down.

But I have a small RAID0 array on my desktop made from 3 SATA laptop 
drives that I use for editing and transcoding home movies.  Through no 
intervention on my part, the drives spin down after not being used for a 
while, and whenever I access the filesystem on that array, there is a 
pause of maybe 2 seconds while the drives spin up, and then the array is 
just fine.

So it seems like it could be done, but I'm just trying to figure out if 
only certain hardware supports the "spindown-without-breaking-the-array" 
feature, or if there is some way to do it I am not aware of.