On Mon, Nov 13, 2017 at 11:40:17AM -0500, Austin S. Hemmelgarn wrote: > On 2017-11-13 11:11, Gene Heskett wrote: > > On Monday 13 November 2017 10:12:47 Austin S. Hemmelgarn wrote: > > > > > On 2017-11-13 09:56, Gene Heskett wrote: > > > > On Monday 13 November 2017 07:19:45 Austin S. Hemmelgarn wrote: > > > > > On 2017-11-11 01:49, Jon LaBadie wrote: > > > > > > Just a thought. My amanda server has seven hard drives > > > > > > dedicated to saving amanda data. Only 2 are typically > > > > > > used (holding and one vtape drive) during an amdump run. > > > > > > Even then, the usage is only for about 3 hours. > > > > > > > > > > > > So there is a lot of electricity and disk drive wear for > > > > > > inactive drives. > > > > > > > > > > > > Can todays drives be unmounted and powered down then > > > > > > when needed, powered up and mounted again? > > > > > > > > > > > > I'm not talking about system hibernation, the system > > > > > > and its other drives still need to be active. > > > > > > > > > > > > Back when 300GB was a big drive I had 2 of them in > > > > > > external USB housings. They shut themselves down > > > > > > on inactivity. When later accessed, there would > > > > > > be about 5-10 seconds delay while the drive spun > > > > > > up and things proceeded normally. > > > > > > > > > > > > That would be a fine arrangement now if it could > > > > > > be mimiced. > > > > > > > > > > Aside from what Stefan mentioned (using hdparam to set the standby > > > > > timeout, check the man page for hdparam as the numbers are not > > > > > exactly sensible), you may consider looking into auto-mounting each > > > > > of the drives, as that can help eliminate things that would keep > > > > > the drives on-line (or make it more obvious that something is still > > > > > using them). > > > > ... > > > > But if I allow the 2TB to be unmounted and self-powered down, once > > daily, what shortening of its life would I be subjected to? In other > > words, how many start-stop cycles can it survive? > > > It's hard to be certain. For what it's worth though, you might want to test > this to be certain that it's actually going to save you energy. It takes a > lot of power to get the platters up to speed, but it doesn't take much to > keep them running at that speed. It might be more advantageous to just > configure the device to idle (that is, park the heads) after some time out > and leave the platters spinning instead of spinning down completely (and it > should result in less wear on the spindle motor). > > In my situation, each of the six data drives is only needed for a 2 week period out of each 12 weeks. Once shutdown, it could be down for 10 weeks.
Jon -- Jon H. LaBadie j...@jgcomp.com 11226 South Shore Rd. (703) 787-0688 (H) Reston, VA 20190 (703) 935-6720 (C)
