usage: fsx [-dfjknqxyACFHKLORUWZ] [-b opnum] [-c Prob] [-h holebdy] [-l flen] [-m start:end] [-o oplen] [-p progressinterval] [-r readbdy] [-s style] [-t truncbdy] [-w writebdy] [-D startingop] [-N numops] [-P dirpath] [-S seed] pname iname
	-b opnum: beginning operation number (default 1)
	-c P: 1 in P chance of file close+open at each op (default infinity)
	-d: debug output for all operations
	-f: flush and invalidate cache after I/O
        -g: deep copy instead of clone
	-h holebdy: 4096 would make discards page aligned (default 1)
	-j: journal replay stress test
	-k: keep data on success (default 0)
	-l flen: the upper bound on file size (default 262144)
	-m startop:endop: monitor (print debug output) specified byte range (default 0:infinity)
	-n: no verifications of file size
	-o oplen: the upper bound on operation size (default 65536)
	-p progressinterval: debug output at specified operation interval
	-q: quieter operation
	-r readbdy: 4096 would make reads page aligned (default 1)
	-s style: 1 gives smaller truncates (default 0)
	-t truncbdy: 4096 would make truncates page aligned (default 1)
	-w writebdy: 4096 would make writes page aligned (default 1)
	-x: preallocate file space before starting, XFS only (default 0)
	-y: synchronize changes to a file
	-C: do not use clone calls
	-D startingop: debug output starting at specified operation
	-H: do not use punch hole calls
	-K: enable krbd mode (use -t and -h too)
	-M: enable rbd-nbd mode (use -t and -h too)
	-L: fsxLite - no file creations & no file size changes
	-N numops: total # operations to do (default infinity)
	-O: use oplen (see -o flag) for every op (default random)
	-P dirpath: save .fsxlog and .fsxgood files in dirpath (default ./)
	-R: read() system calls only (mapped reads disabled)
	-S seed: for random # generator (default 1) 0 gets timestamp
	-U: disable randomized striping
	-W: mapped write operations DISabled
	-Z: O_DIRECT (use -R, -W, -r and -w too)
	poolname: this is REQUIRED (no default)
	imagename: this is REQUIRED (no default)