On 2017-11-13 14:51, Jon LaBadie wrote:
On Mon, Nov 13, 2017 at 02:04:42PM -0500, Gene Heskett wrote:
On Monday 13 November 2017 13:42:13 Jon LaBadie wrote:
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
Which is more than enough time for stiction to appear if the heads are
not parked off disk.
Don't today's drives automatically park heads?
I don't think there were ever any (at least, not ATA or SAS) that didn't
when they went into standby. In fact, I've never seen a modern style
hard disk with 'voice coil' style actuators that didn't automatically
park the heads (and part of my job is tearing apart old hard drives
prior to physical media destruction, so I've seen my fair share of them).
