Author Archive

I experienced a weird problem whereby no images were loading in Safari (yet Flash was working) but everything was fine in Firefox. I tried cleaning out caches, and reset virtually everything. The real problem turned out that I had accidentally checked the item “Disable Images” under the “Develop” menu. I...
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Download a simulator. You will need a NOW (NetApp On the Web) account to download. http://now.netapp.com/NOW/cgi-bin/simulator I am using a Linux virtual machine inside Virtual Box, so I connect to that Linux machine and copy over the tarfile, that I downloaded to my mac. An alternative would be do download it from within the...
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When collecting network traces to solve performance problems, we need to balance the need to capture enough data to re-construct the upper protocols with the need to limit the amount of trace data collected overall. When capturing NFS traffic, the packet size can grow to be quite large, since the NFS packets will...
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On Janurary 5th 2010 I gave a short presentation on the FileBench workload modeling tool to the RTP OpenSolaris group. Click on the slide to advance. The “Slides” link will take you to an HTML version. Slides
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Sometimes you might want to change the “type” of a disk within Solaris. The “type” of the disk is stored on the disk itself, along with the partition table (presumably in the VTOC in the first part of the disk). For the purpose of this post, I use disk “name” and “type” interchangeably. In...
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A set of recorded presentations from the Velocity 09 conference, many of which are related to performance. Particularly “Internet Scale” problems. Here’s the link: Velocity 2009
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Some snaps from the top of Mt. Occoneechee. Click “Read more” to see slideshow.
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A 2004 paper from Neil Gunther which essentially discusses the pitfalls of relying on observed date without applying the known performance laws (most notably little’s law) to the problem at hand. PDF The original link to arXiv.org (whatever that is)
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These guys at ‘backblaze’ claim to be able to provide 67TB for $7,867 based on 45 SATA drives, RAID6 (Linux) and JFS. The hardware design which is presented in the blog as a how-to uses vertically stacked drives and looks very much like the Sun ‘Thumper’ (X4500) device which I first saw...
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Not sure how well known this trick is, but it is possible to figure out the vendor of a particular NIC by looking at the first few digits of the MAC address. We used to use this when I worked at Sun to figure out if the customers were using pukka Sun NICs...
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