Re: modprobe mlx5_core on OCI bare-metal instance causes unrecoverable hang and I/O error

[Mitchell Augustin]

*facepalm*

Thanks, I can't believe that wasn't my first thought as soon as I
learned these instances were using iSCSI. That's almost certainly what
is happening on this OCI instance, since the host adapter for its
iSCSI transport is a ConnectX card.

The fact that I was able to see similar behavior once on a machine
booted from a local disk (in the A100 test I mentioned) is still
confusing though. I'll update this thread if I can figure out a
reliable way to reproduce that behavior.


On Fri, Feb 7, 2025 at 1:01 PM Jason Gunthorpe <jgg@xxxxxxxx> wrote:
>
> On Fri, Feb 07, 2025 at 10:02:46AM -0600, Mitchell Augustin wrote:
> > > Is it using iscsi/srp/nfs/etc for any filesystems?
> >
> > Yes, dev sda is using iSCSI:
>
> If you remove the driver that is providing transport for your
> filesystem the system will hang like you showed.
>
> It can be done, but the process sequencing the load/unload has to be
> entirely contained to a tmpfs so it doesn't become blocked on IO that
> cannot complete.
>
> Jason



-- 
Mitchell Augustin
Software Engineer - Ubuntu Partner Engineering