I believe the right solution is to set the default in the kernel, not in mkfs, it should be possible to change lazy-sb to no-lazy-sb and only flag when we actually want to disable it. FS mounted with lazy-sb, should be (if unmounted cleanly) mountable by a non-lazy-aware kernel, (and if not unmounted cleanly, then repair should be able to fix it). I'll try to get that pushed for next week in kernel and xfsprogs. Cheers, -- Niv Sardi