Re: possible usb3-connected hard drive spin down causing lag

On Thu, Nov 26, 2020 at 2:47 AM Dimitry Andric <dim_at_freebsd.org> wrote:

> On 26 Nov 2020, at 01:10, tech-lists <tech-lists_at_zyxst.net> wrote:
> >
> > I have a usb3-connected harddrive. dmesg shows this:
> > [...]
> > da0: <ADATA HD710 0> Fixed Direct Access SPC-4 SCSI device
> > [...]
> >
> > running current-r367806-arm64
> >
> > I think it might be auto-spinning-down or auto-sleeping. It's
> > making initial interaction lag of 2-3 seconds. Is there a sysctl or
> something somewhere where I can tell it to never sleep? Or is that
> something I'd need to contact the manufacturer about? Or is there an
> alternative strategy like tmpfs. It's not a "green" drive but I guess it
> might
> > be "green" in that it's usb3 powered.
> >
> > I have vfs.read_max=128 in /etc/sysctl.conf
> > zdb has ashift=12
> >
> > In case it's relevant, the filesystem on the disk is zfs. Once
> > "woken up", inferaction is quick, as expected.
> > thanks,
>
> I have been using the attached rc.d script for a long time now, which
> uses camcontrol(8)'s "apm" and "aam" commands to set drives to 'maximum
> performance' (aka don't try to save power by shutting down all the
> time).
>
> Just drop this into /usr/local/etc/rc.d, and add something like the
> following to your rc.conf:
>
> camperf_devices="da0 da1"
> camperf_enable="YES"
>
> You can also manually start the rc.d script by running:
>
> sudo service camperf start
>

Should we have this, or a similar 'standby' setting as well in base? this
question comes up a lot...

Warner