On Mon, Nov 13, 2023 at 08:58:55PM +1100, eyal@xxxxxxxxxxxxxx wrote: > [trimmed] > > > [0]: https://bugzilla.kernel.org/show_bug.cgi?id=217965 > > Reading this bugzilla, an extra info bit. This has not changed for years (I have daily records). > > $ mount|grep data1 > /dev/md127 on /data1 type ext4 (rw,noatime,stripe=640) Yeah, afaiui, one of the theories in the bug suggests that a recently introduced block allocation improvement made matters worse for any kind of stride/stripe setting <> 0. So if you dial your kernel version back to before that was made (6.4 seems to be unaffacted, iirc), you will probably regain the performance loss you observe and reported here on list. FWIW, I briefly played around with an artificial dataset on tmpfs-backed loop devices configured in RAID5 where I was (re)setting the superblock-configured stride-setting, and did not lose any data by toggling it between 0 and <some_other_value> (256 in my case) multiple times. So I would assume that to be a safe operation in principle ;) -- with best regards: - Johannes Truschnigg ( johannes@xxxxxxxxxxxxxxx ) www: https://johannes.truschnigg.info/ phone: +436502133337 xmpp: johannes@xxxxxxxxxxxxxxx
Attachment:
signature.asc
Description: PGP signature
