will replace it, change the indicator character from '|' to 'O', and increase the update frequency.
bytes for regular files. Adjust all other default values accordingly.
for smaller block sizes.
fixed amount of data.
transactions, as they will always be either perfectly aligned or short. Increase STEP to MAXSIZE * 4; having STEP equal to MAXSIZE means that the last round actually tests sequential reading / writing, which is not what we're after. Instead of testing all offsets from 0 to size, test 0 and power-of-two multiples of BSIZE, since we assume that the physical block size is a power-of-two multiple of BSIZE. This should both shorten the test's run time and improve the significance of its output.
designed to reveal the physical block size of a disk. It performs a series of staggered reads and / or writes of different lengths at different alignments. The idea is that a disk that has a large physical blocksize but simulates a smaller one will perform poorly, due to read-modify-write, except when both the I/O size and the offset are multiples of the physical block size. The program supports read-only, write-only and read-write tests. The default is write-only. A read-write test is probably not very useful, because it primes the cache in cases where the disk would actually perform an extra read. A read-only test is useless except as a quick way to verify that the program works. Note that the program currently assumes a logical block size of 512 bytes and that the parameters (size range, interval and iterations) are hardcoded.