On Wed, Sep 30, 2020 at 05:03:28AM +0100, Wols Lists wrote: > uname -a ??? Linux vega.stars 4.9.237-vega #1 SMP Tue Sep 29 23:52:36 CEST 2020 x86_64 GNU/Linux This is a stock 4.9.237 kernel that I compiled with gcc version 4.8.4 (Debian 4.8.4-1). RAID-related options in the config are: CONFIG_MD=y CONFIG_BLK_DEV_MD=y CONFIG_MD_AUTODETECT=y CONFIG_MD_LINEAR=m CONFIG_MD_RAID0=y CONFIG_MD_RAID1=y CONFIG_MD_RAID10=m CONFIG_MD_RAID456=m CONFIG_MD_MULTIPATH=m CONFIG_MD_FAULTY=m # CONFIG_MD_CLUSTER is not set CONFIG_ASYNC_RAID6_RECOV=m CONFIG_RAID6_PQ=m (I can, of course, put the full config somewhere). > mdadm --version ??? mdadm - v3.4 - 28th January 2016 (This is the version from Debian 9.13 "stretch" (aka oldstable).) > https://raid.wiki.kernel.org/index.php/Linux_Raid#When_Things_Go_Wrogn I should have clarified that I suffered no data loss. Since the attempt to reshape simply does nothing (and the underlying filesystem was read-only just in case), I was able to simply recreate the RAID5 array with --assume-clean. But I'd really like to convert to RAID6. I can, of course, provide detailed information on the disks, but since I can reproduce the problem on loopback devices, I imagine this isn't too relevant. > I'm guessing you're on an older version of Ubuntu / Debian ? Yes, Debian 9.13 "stretch" (aka oldstable). -- David A. Madore ( http://www.madore.org/~david/ )
