Hi, Thanks to Rick Mohr for relaying his experience. I now need to sort out correct mount options for combined MDT/MGS (was w/ failover and quotas). I think the failover.node is the bad option but am not sure of the correct syntax. Presumably I will have to fix the params with tunefs.lustre for the OSTs as well... I now have: Debian 6 Lustre 2.4.3 OFED 3.5.2 RHEL6 kernel e2fsprogs-1.42.9.wc1 I can mount with ldiskfs but mounting as lustre complains about bad options. arg[0] = /sbin/mount.lustre arg[1] = -v arg[2] = -o arg[3] = rw arg[4] = /dev/drbd0 arg[5] = /mnt source = /dev/drbd0 (/dev/drbd0), target = /mnt options = rw checking for existing Lustre data: found Reading CONFIGS/mountdata mounting device /dev/drbd0 at /mnt, flags=0x1000000 options=osd=osd-ldiskfs,errors=remount-ro,iopen_nopriv,user_xattr,mgs,writeconf,param=failover.node=10.16.10.231@o2ib,10.0.11.231@tcp,param=mdt.quota_type=ug2,param=mdt.group_upcall=/usr/sbin/l_getgroups,svname=lustre-MDT0000,device=/dev/drbd0 mount.lustre: mount /dev/drbd0 at /mnt failed: Invalid argument retries left: 0 mount.lustre: mount /dev/drbd0 at /mnt failed: Invalid argument This may have multiple causes. Are the mount options correct? Check the syslog for more info. tunefs.lustre --writeconf --dryrun /dev/drbd0 --> checking for existing Lustre data: found Reading CONFIGS/mountdata Read previous values: Target: lustre-MDT0000 Index: 0 Lustre FS: lustre Mount type: ldiskfs Flags: 0x105 (MDT MGS writeconf ) Persistent mount opts: errors=remount-ro,iopen_nopriv,user_xattr Parameters: failover.node=10.16.10.231@o2ib,10.0.11.231@tcp mdt.quota_type=ug2 mdt.group_upcall=/usr/sbin/l_getgroups Permanent disk data: Target: lustre=MDT0000 Index: 0 Lustre FS: lustre Mount type: ldiskfs Flags: 0x105 (MDT MGS writeconf ) Persistent mount opts: errors=remount-ro,iopen_nopriv,user_xattr Parameters: failover.node=10.16.10.231@o2ib,10.0.11.231@tcp mdt.quota_type=ug2 mdt.group_upcall=/usr/sbin/l_getgroups exiting before disk write. Regards, -- Gretchen Zwart UMass Astronomy Dept. 619E Lederle 710 North Pleasant ST Amherst,MA 01003 (413) 577-2108