On Mon, May 07, 2018 at 11:12:16PM +0200, T_POL wrote:
On Mon, 7 May 2018 12:54:48 -0700
Rick Stevens <ricks(a)alldigital.com> wrote:
> On 05/04/2018 02:58 PM, T_POL wrote:
> > On Fri, 4 May 2018 14:20:13 -0700
> > Rick Stevens <ricks(a)alldigital.com> wrote:
> > Both "udevadm" commands lists nothing after
plugging the drive.
> > The only way to make the drive detected is to run as root the following command
:
> >
> > "echo "- - -" > /sys/class/scsi_host/host5/scan"
> >
> > Found it with google :)
>
> Yeah, google is your friend (at times). That would trigger a SCSI bus
> scan.
>
> > Immediately after that, disk is detected.
>
> It's odd that it's not seen at all except if plugged in at boot. Sounds
> like a bug, although I don't know if it'd be in the SCSI driver, hotplug
> code or kernel itself. I'd sure bugzilla it.
well, never opened a bugzilla in my (long) life.
May be this will be the first time.
Are you sure there's nothing else in the log files?
It could be an odd timing bug, such that delaying a bit before scanning avoids the
problem.
You can also enable scsi debug output, plug it in, see that it's not found, manually
scan it, and check the output.
Then boot with scsi debug enabled, and compare the output to that seen during the
hotplug of the device.
Warning: enabling scsi logging can make your system unusable!
Before running with logging enabled:
Disable systemd logging via:
systemctl stop systemd-journald
Disable (old style, not on by default) syslog logging via:
systemctl stop syslog
When booting (best to edit the boot line manually, less your screw it up), put
scsi_logging_level=1 to enable scsi logging, boot to run level 1, and stop logging
before fully booting - before logging to disk is enabled. i.e. on the boot line,
append:
scsi_logging_level=1 1
After booting, or for testing, or to try and reset it to zero because you left
syslog or wtf running before enabling debug output:
echo 1 > /sys/module/scsi_mod/parameters/scsi_logging_level
echo 0 > /sys/module/scsi_mod/parameters/scsi_logging_level
You can try other debug levels too (up to 4).
And then post your results to linux-scsi.
-- Patrick