QA output created by 250
*** create loop mount point
*** mkfs loop file (size=50g)
meta-data=DDEV isize=XXX agcount=N, agsize=XXX blks
data     = bsize=XXX blocks=XXX, imaxpct=PCT
         = sunit=XXX swidth=XXX, unwritten=X
naming   =VERN bsize=XXX
log      =LDEV bsize=XXX blocks=XXX
realtime =RDEV extsz=XXX blocks=XXX, rtextents=XXX
*** mount loop filesystem
*** preallocate large file
*** unmount loop filesystem
*** check loop filesystem
*** done

