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

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.

-- 
Gary Jennejohn