What steps did you take to do this?

This was an existing 2.1.6, upgraded to 2.4.2 while stil using combined MDS/MGS.

MGS was split using:

mkfs.lustre --mgs <new-mgs-device>

mount -t ldiskfs <old-mgs-device> /mnt/1

mount -t ldiskfs <new-mgs-device> /mnt/2

cp -r /mnt/1/CONFIGS/testfs-* /mnt/2/CONFIGS

then I did --nomgs on the previous combo device.

Actually the entire filesystem came up correctly after that: MGT MDT 4 x OSTs.

The system was taken down for hardware maintenance and I encountered this "AT" osp issue on restart.

The system was cleanly unmounted (or so I thought).

Thanks.