Re: [REGRESSION] 6.7.1: md: raid5 hang and unresponsive system; successfully bisected

From: Roman Mamedov
Date: Fri Jan 26 2024 - 11:30:22 EST


On Fri, 26 Jan 2024 00:30:46 -0300
Carlos Carvalho <carlos@xxxxxxxxxxxxxx> wrote:

> Dan Moulding (dan@xxxxxxxx) wrote on Thu, Jan 25, 2024 at 05:31:30PM -03:
> > I then created an ext4 file system on the "data" volume, mounted it, and used
> > "dd" to copy 1MiB blocks from /dev/urandom to a file on the "data" file
> > system, and just let it run. Eventually "dd" hangs and top shows that
> > md0_raid5 is using 100% CPU.
>
> It's known that ext4 has these symptoms with parity raid. To make sure it's a
> raid problem you should try another filesystem or remount it with stripe=0.

If Ext4 wouldn't work properly on parity RAID, then it is a bug that should be
tracked down and fixed, not worked around by using a different FS. I am in
disbelief you are seriously suggesting that, and to be honest really doubt
there is any such high-profile "known" issue that stays unfixed and is just
commonly worked around.

--
With respect,
Roman