ZFS and power management

[Karl Denninger]

On 1/5/2020 16:10, Peter wrote:
> On Wed, 18 Dec 2019 17:22:16 +0100, Karl Denninger
> <karl at denninger.net> wrote:
>
>> I'm curious if anyone has come up with a way to do this...
>>
>> I have a system here that has two pools -- one comprised of SSD disks
>> that are the "most commonly used" things including user home directories
>> and mailboxes, and another that is comprised of very large things that
>> are far less-commonly used (e.g. video data files, media, build
>> environments for various devices, etc.)
>
> I'm using such a configuration for more than 10 years already, and
> didn't perceive the problems You describe.
> Disks are powered down with gstopd or other means, and they stay
> powered down until filesystems in the pool are actively accessed.
> A difficulty for me was that postgres autovacuum must be completeley
> disabled if there are tablespaces on the quiesced pools. Another thing
> that comes to mind is smartctl in daemon mode (but I never used that).
> There are probably a whole bunch more of potential culprits, so I
> suggest You work thru all the housekeeping stuff (daemons, cronjobs,
> etc.) to find it.

I found a number of things and managed to kill them off in terms of
active access, and now it is behaving.  I'm using "camcontrol idle -t
240 da{xxx}", which interestingly enough appears NOT to survive a
reboot, but otherwise does what's expected.

-- 
Karl Denninger
karl at denninger.net <mailto:karl at denninger.net>
/The Market Ticker/
/[S/MIME encrypted email preferred]/
-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 4897 bytes
Desc: S/MIME Cryptographic Signature
URL: <http://lists.freebsd.org/pipermail/freebsd-stable/attachments/20200105/baedd6d1/attachment.bin>