Re: PROBLEM: repeatable lockup on RAID-6 with LUKS dm-crypt on NVMe devices when rsyncing many files

["John Stoffel" <john@stoffel.org>]

>>>>> "Christian" == Christian Theune <ct@flyingcircus.io> writes:

> Hi,
>> On 14. Aug 2024, at 10:53, Christian Theune <ct@flyingcircus.io> wrote:
>> 
>> Hi,
>> 
>>> On 12. Aug 2024, at 20:37, John Stoffel <john@stoffel.org> wrote:
>>> 
>>> I'd probably just do the RAID6 tests first, get them out of the way.  
>> 
>> Alright, those are running right now - I’ll let you know what happens.

> I’m not making progress here. I can’t reproduce those on in-memory
> loopback raid 6. However: i can’t fully produce the rsync. For me
> this only triggered after around 1.5hs of progress on the NVMe which
> resulted in the hangup. I can only create around 20 GiB worth of
> raid 6 volume on this machine. I’ve tried running rsync until it
> exhausts the space, deleting the content and running rsync again,
> but I feel like this isn’t suffient to trigger the issue. :(

You're running on the older 5.13.x kernel or the newer 6.x kernel?  

> I’m trying to find whether any specific pattern in the files around
> the time it locks up might be relevant here and try to run the rsync
> over that portion.

That's a good idea.  Do you have highly compressed files which are
maybe exploding in size when put into LUKS encrypted partitions?  Just
a random thought, not a real idea.

> On the plus side, I have a script now that can create the various
> loopback settings quickly, so I can try out things as needed. Not
> that valuable without a reproducer, yet, though.

Yay!  Please share it.