make kernel ignore broken SATA disk

[Slawa Olhovchenkov]

On Sun, Apr 12, 2020 at 07:08:06PM +0200, Stefan Bethke wrote:

> Am 12.04.2020 um 19:03 schrieb Slawa Olhovchenkov <slw at zxy.spb.ru>:
> > 
> > On Sun, Apr 12, 2020 at 06:38:10PM +0200, Stefan Bethke wrote:
> > 
> >> 
> >> 
> >>> Am 12.04.2020 um 18:31 schrieb Slawa Olhovchenkov <slw at zxy.spb.ru>:
> >>> 
> >>> On Sun, Apr 12, 2020 at 06:24:09PM +0200, Stefan Bethke wrote:
> >>> 
> >>>> Am 12.04.2020 um 17:43 schrieb Slawa Olhovchenkov <slw at zxy.spb.ru>:
> >>>>> 
> >>>>> On Sun, Apr 12, 2020 at 04:37:06PM +0200, Stefan Bethke wrote:
> >>>>> 
> >>>>>> I have a server I don't have physical access to right now, which has a broken SATA disk that produces mostly errors (but not entirely).
> >>>>>> 
> >>>>>> The disk has two partitions that are part of a zpool each. I can't bring the system up with this disk being online, because ZFS is trying its darndest to use it.
> >>>>>> 
> >>>>>> I already renamed the GPT partitions in the hope that ZFS would not find them anymore, but it does.
> >>>>>> 
> >>>>>> I can't gpart destroy -f ada1 because "device busy".
> >>>>>> 
> >>>>>> Is there a way, ideally in the loader, to tell the kernel to ignore ada1 and/or ahcich5? Or can I force ZFS some other way to ignore the disk? I do have a spare disk I can use to replace the failed one, but I can't get the machine into a state where I could even issue the zpool replace command.
> >>>>> 
> >>>>> `zpool offline pool device` if you have enoght redundancy?
> >>>> 
> >>>> I do, but the command doesn't return. Instead, I'm getting loads of sata error message.
> >>> 
> >>> What you zpool configuration?
> >> 
> >> This is from the working system. The identifiers are slightly different, but the structure is identical.
> > 
> > what about `zpool detach <pool> <device>` ?
> 
> Now I can't boot into single user mode anymore, ZFS just waits forever, and the kernel is printing an endless chain of SATA error messages.
> 
> I really need a way to remove the broken disk before ZFS tries to access it, or a way to stop ZFS from try to access the disk.

This disk only part of mirror? ZIL is OK?