Strange SATA Disk Performance

Below is a GNUPlot graph of ZCAV output from a 250G SATA disk. The disk has something wrong with it (other disks of the same brand in machines of the same configuration give more regular graphs). The expected graph will start high on the Y scale (MB/s) and steadily drop as the reads go to […]

paper about ZCAV

This paper by Rodney Van Meter about ZCAV (Zoned Constant Angular Velocity) in hard drives is very interesting. It predates my work by about four years and includes some interesting methods of collecting data that I never considered.

One interesting thing is that apparently on some SCSI drives you can get the drive to tell […]

new release of postal

Today I have released a significant new version of my mail server benchmark Postal! The list of changes is below:

Added new program bhm to listen on port 25 and send mail to /dev/null. This allows testing mail relay systems. Fixed a minor bug in reporting when compiled without SSL. Made postal write the date […]


Yesterday I gave a presentation at OSDC in Melbourne about my Postal mail server benchmark suite. The paper was about my new benchmark program BHM for testing the performance of mail relay systems and some of the things I learned by running it. I will put the paper on my Postal site in the near […]

Ruxcon and SLUG

This weekend I was in Sydney for Ruxcon. Ruxcon is a computer security conference with a focus on penetration testing and related skills.

The presentation on Unusual Bugs by Ilya van Sprudel was particularly interesting. He spoke about a number of issues that could do with some improvement in Linux, I will file some bug […]