Just a thought about this feature...
I guess once solid state disks become common place and booting from USB etc like 3i this wont be a problem but does anyone think or agree that DPM will have a detrimental affect on the components within the physical host?
Im just playing with it in DEV at the moment and it seems very realiable but is a server turning on and off say every day going to have as long a life as a box that sits with the Disk Spindles going continuously?
You point out exactly why it could be a disk-health issue long term.
I would say though, that if a server is really turning on and off that frequently, you shouldn't use DPM - its probably not worth it.
I know exactly what you mean about hard disks,
You sound as if you have been in this game quite a while, as I have,
Basically the idea that Hard Disk Drives dont like to be turned on and off is out of date and redundant. Unless you are using servers that are more then 3 or 4 years old this should not concern you,
Modern U320, Fibre, SATA and SAS Hard Drives are passed a standby request from their host, they then stand down to a sort of 'domant mode' for want of a better phrase, they spin down to a much lower RPM, then they shut down completely,
In short modern hard disks are designed for constant power downs and power ups,
You would only develop a problem if the disk was repeptitively ripped from it power supply whilst being accessed.