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

From: Dimitry Andric <dim_at_FreeBSD.org>
Date: Thu, 26 Nov 2020 19:37:47 +0100
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".

-Dimitry


Received on Thu Nov 26 2020 - 17:37:57 UTC

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