On Fri, 2021-03-26 at 21:46 -0600, Chris Murphy wrote:
On Fri, Mar 26, 2021 at 5:21 PM Patrick O'Callaghan
<pocallaghan(a)gmail.com> wrote:
>
> I have an external USB-3 2-disk docking station, and a script which
> can
> power up and down the drives as needed.
>
> I have a systemd automount unit that correctly powers up the dock
> when
> accessed, then mounts the drives (thanks Ed).
>
> After an idle time, automount unmounts the drives. A script detects
> when this happens and powers them down ... *at which point they
> immediately power up again, and remain up until I intervene
> manually,
> even though they are unmounted*.
>
> This never happens if I run the script directly from the command
> line
> (i.e. the drives power down and stay down).
>
> Clearly the docking unit isn't just doing this flakily on its own.
> Something is making it happen, and I've no idea how to discover
> what it
> is except that it seems to be correlated with systemd in some way.
>
> All of the above is 100% reproducible.
>
> I'm open to suggestions if anyone has any ideas.
smartd?
I use this line in smartd.conf to keep it from waking up the drive
all the time.
/dev/disk/by-id/wwn-0x5000c500a93cae8a -l selftest -s L/../15/./22 -n
standby,250
Since it's unmounted, fatrace won't work, but blktrace will..
blktrace -d /dev/sdb -o - | blkparse -i -
It will generate a lot of lines but it'll also report the process
that's sending commands to the drive.
OK, that looks like it's worth investigating.
poc