Fio
Random read/write performance
fio --randrepeat=1 --ioengine=posixaio --direct=1 --gtod_reduce=1 --name=test --filename=test --bs=4k --iodepth=64 --size=4G --readwrite=randrw --rwmixread=75
Random read performance
fio --randrepeat=1 --ioengine=posixaio --direct=1 --gtod_reduce=1 --name=test --filename=test --bs=4k --iodepth=64 --size=4G --readwrite=randread
Random write performance
fio --randrepeat=1 --ioengine=posixaio --direct=1 --gtod_reduce=1 --name=test --filename=test --bs=4k --iodepth=64 --size=4G --readwrite=randwrite
(On MacOS we must use posixaio ioengine. If you are on running some different flavour of Unix just replace –ioengine=posixaio with eg. –ioengine=libaio for Ubuntu)