For a first time completed S.M.A.R.T captive test

[Domagoj Smolčić]

On Wed, 17 Jul 2019 19:37:25 -0700
Ravi Pokala <rpokala at freebsd.org> wrote:

> Hi Domagoj
> 
> The "captive" test is blocking -- meaning the drive won't indicate
> command completion for multiple hours in the case of modern large
> HDDs -- so the FreeBSD driver will almost certainly timeout before
> completion. That in turn will trigger recovery mechanisms, which will
> include a soft-reset, which is where the "Interrupted (host reset)"
> comes from.
> 
> You almost always want to do the "off-line" test; that tells the
> drive firmware to start the test and run it in the background. It
> will indicate command completion in a second or two, but the test
> will still take the same amount of time. But in the case of the
> "off-line" test, the drive is responsive to the host even while the
> test runs. When the drive receives a command from the host, it will
> pause the test, service the host request, and then resume the test.

Thanks. I knew that part. It was a captive test that was a riddle.

> I work at a storage company, I've been running ATA self-test for 15+
> years, and I've never understood why the "captive" test even exists.
> *Maybe* there were dedicated drive test systems that had huge
> timeouts, back in the PATA days? Or even horrible DOS stuff that
> didn't even have a timeout, and just waited for the interrupt
> forever? <shrug>

I can understand devs of smartmontools, like, if code for captive test
already exists, why to remove it?
But then again, it just sends a test request to drive's firmware, so ...
Why are all corporations, which manufacture storage devices, still
write drive's firmware with captive test ability?

> In any case, I would simply not bother with the "captive" test modes.

Now that all is clear and I succeeded in completing a captive test,
purely out of curiosity, I won't bother anymore.
 
> -Ravi (rpokala@) <wearing Panasas hat>


Domagoj Smolčić