a) iozone - Filesystem Benchmark Tool
Simple test using -a option to select full automatic mode, with -g to extend the maximum file size to be twice your system's main memory size:
time iozone -a -g 4G >|/tmp/iozone-stdout.txt
The size specified with any option can have the m or g (not case-sensitive) postfix to specify units of megabytes or gigabytes. Wrapping the iozone command with time command allows us to see how long it took.
You can use the -n option to specify the minimum file size that the automatic mode will use during testing. Normally testing will start with 64KB files and increase the size by doubling it each iteration. Using -n can save some time and generate more targeted benchmarks if you are interested in only larger files that cannot possibly fit into the system buffer caches. You can use the -s option instead of -g to only test files of a specific nominated size. The below command will test only using files of 4GB in size and records from 4KB to 256KB in size.
time iozone -a -s 4G -q 4 -y 256 >|/tmp/iozone-stdout.txt