Request for Disk Performance Measurement Tools

[Cory Myers]

I am looking for any pointers to software that will allow me to measure
disk performance on a number of Sun and disk combinations that we
currently have.  I am interested in both read and write performance both
through the file system and to raw disks and both for bursts and sustained
rates.  I would be especially grateful for software that included source
code so that I can learn whatever tricks (if any) there are to maximizing
the throughput.  Thanks in advance,

        Cory Myers
        cory%aaec1.uucp at dspvax.mit.edu