Tonight I gave a talk at the local opensolaris users group titled “DTrace for SysAdmins: An introduction to the DTraceToolkit.” I would like to thank everyone for coming out, and for putting up with my broken voice (I am currently getting over a cold). I put the presentation slides up on prefetch.net, and I hope [...]
I got sick last Friday, and have been stuck at home all weekend recovering. While I was resting in bed yesterday, I set iTunes to play random music from my CD collection. iTunes was playing musical artists who I haven’t listened to in several years (I can’t recall the last time I actually listened to [...]
I recently spent some time reading through the grub source code and the real mode assembly that resides in the MBR (master boot record). As I was reading though an explanation of the MBR real mode asembly code, I was amazed at how much cool stuff was packed into the 512-bytes that makes up the [...]
I have a few Redhat Linux servers that log application data to one or more logfiles in /var/log. For some reason Redhat Linux doesn’t compress the logfiles in /var/log by default, which can be a problem if your logging a lot of information, or if you need to keep logfiles around for historical reasons. To [...]
With the introduction of OpenSSH 4.3p2, Darren Tucker introduced the “Match” keyword. This super nifty keyword can be used to limit features to specific users, hosts and groups, and allows administrators to enforce granular feature access (e.g., key-based authentication can only be used from specific hosts or subnets). To use the Match feature, the Match [...]
OpenBSD has a number of nifty utilities, and I happened to come across the systat(1) utility this weekend while looking for an executable in /usr/bin. Systat prints out performance data in an ncurses display, and can be used to view CPU saturation, I/O statistics, swap utilization, netstat data, and MBUF and network interface utilization. The [...]
