Re: [PATCH] md: warn about using another MD array as write journal

It has been two months since I last reported the state of the issue:

On 17. 03. 21 16:55, Vojtech Myslivec wrote:
 > Thanks a lot Manuel for your findings and information.
 >
 > I have moved journal from logical volume on RAID1 to a plain partition
 > on a SSD and I will monitor the state.

So, we run the MD level 6 array (/dev/md1) with journal device on
a plain partition of one of SSD disk (/dev/sdh5) now. See attached files
for more details.


Since then (March 17th), our discussed issue happened "only" three 
times. First occurrence was on April 21st, 5 weeks after moving the journal.

*I can confirm that the issue still persist, but it is definitely less
frequent.*



On 22. 03. 21 18:13, Song Liu wrote:
 > Thanks for the information. Quick question, does the kernel have the
 > following change?
 >
 > commit c9020e64cf33f2dd5b2a7295f2bfea787279218a Author: Song
 > Liu[off-list ref] Date:   9 months ago
 >
 > ...

We run latest available kernel from "Debian backports" distribution
repository, that is Linux version 5.10 currently. I checked that we had
kernel 5.10 as well on March, when I moved the journal.

If I checked it well, this particular patch is part of kernel 5.9
already.



Maybe unrelated, but I noticed this log message just after our "unstuck"
script performed some random I/O operation (just as I described before 
in this e-mail thread):

     May 2 ... kernel: [2035647.004554] md: md1: data-check done.



I would provide more information if needed. Thanks for any new info.

Vojtech Myslivec