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

On Thu, 26 Nov 2020 10:12:06 +0100
Gary Jennejohn <gljennjohn_at_gmail.com> wrote:

> On Thu, 26 Nov 2020 01:14:02 -0700
> Warner Losh <imp_at_bsdimp.com> wrote:
> 
> > On Thu, Nov 26, 2020 at 1:07 AM Gary Jennejohn
> > <gljennjohn_at_gmail.com> wrote: 
> > > On Thu, 26 Nov 2020 00:10:40 +0000
> > > tech-lists <tech-lists_at_zyxst.net> wrote:
> > >    
> > > > Hi,
> > > >
> > > > 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'd be interested in an answer to this question myself.  I have
> > > several USB-attached UFS2 disks which spin down after a few
> > > minutes.
> > >
> > > But, based on some quick searches, this behavior is either a
> > > "feature" of the disk itself - seems common with so-called green
> > > disks - or of the controller in the external enclosure or docking
> > > station.
> > >
> > > This behavior makes sense for drives used with laptops, but for
> > > desktop computers not so useful.
> > >
> > > There are some sysctl's relevant to spindown, but they appear to
> > > only come into play during suspend or shutdown.  The ones
> > > relevant to USB which I found are:
> > >
> > > kern.cam.ada.spindown_suspend: Spin down upon suspend
> > > kern.cam.ada.spindown_shutdown: Spin down upon shutdown
> > >
> > > There may be commands which a user can send the disk/controller to
> > > disable this behavior, but I didn't find any with my simple
> > > searches. 
> > 
> > For SAS drives, there's a mode page that controls this behavior.
> > 
> > You might see if the sysutil/ataidle port/package does what you
> > want. 
> 
> Thanks, Warner, but that port is not in my HEAD ports tree.  It's
> also not in the HEAD pkg repository.  Many the name has changed?
> 
> My disks are all SATA in various USB3 enclosures/docking stations.
> 

I also used ataidle in the past, but it was removed from the ports tree
in 2018 (see MOVED).

Since then, I'm using camcontrol to set standby timeout values on my
SATA drives, I never tried it on USB devices though.

Example:

/sbin/camcontrol standby /dev/da2 -v -t 1800

Best,
Michael


-- 
Michael Gmelin