possible usb3-connected hard drive spin down causing lag

[Gary Jennejohn]

On Thu, 26 Nov 2020 19:37:47 +0100
Dimitry Andric <dim at FreeBSD.org> wrote:

> On 26 Nov 2020, at 19:21, Gary Jennejohn <gljennjohn at gmail.com> wrote:
> > 
> > On Thu, 26 Nov 2020 10:44:19 -0700
> > Warner Losh <imp at bsdimp.com> wrote:  
> ...
> >>> Example:
> >>> 
> >>> /sbin/camcontrol standby /dev/da2 -v -t 1800  
> >> 
> >> 
> >> Perfect! I've not had to deal with sata disks that did this since the
> >> ataidle days. I looked in camcontrol before suggesting it, but somehow
> >> missed this... Glad I posted a bogus answer (sorry about that), since I
> >> learned something new.
> >>   
> > 
> > camcontrol unfortuantely doesn't work with my USB3 enclosures.  I
> > suspect that the USB3-to-SATA bridge controller is doing its own thing
> > and camcontrol has no effect on its behavior.  Not tragic for me since
> > I use these disks primarily for backups.  But for someone using a USB
> > attached disk as a primary file system this behavior will definitely be
> > a PITA.  
> 
> In this case it's about ATA commands being passed though the USB bridge.
> Does "camcontrol identify daX" fail in your case too?
> 
> I have used quite a bunch of different USB disks, mostly from WD or
> Seagate, and these come with varying qualities of USB-SATA bridges in
> them. But all of them work with "camcontrol identify".
> 

camcontrol identify does work.  The enclosure I tested has an ASMedia
asm1153e bridge in it.  This one idles the disk after a few minutes.

-- 
Gary Jennejohn