Archive
Posts from 2007
Monitoring Linux server performance with nmon
I recently came across Nigel's monitor (nmon), which is an awesome text-based tool for visualizing a variety of CPU, memory, network and kernel performance data on Linux hosts. Nmon can be be run the without any arguments to display a base screen with CPU performance counters, or you can export the NMON environment variable with a list of performance counters you want displayed (you can also enable additional performance counters by typing the key that corresponds to the counter in the nmon display): Once nmon fires up, you will be greeted with a screen similar to the following: Nmon is a great piece of software, and I am hopeful more distributions will include it in the future.
$ read more →Solaris SMART support is finally becoming a reality!!
A while back I wrote a blog entry about the lack of SMART support in Solaris. Just recently, Eric Schrock added a FMA disk-transport diagnosis engine, which provides generic SMART monitoring as part of the base operating system. The disk-transport diagnosis engine currently only supports SATA disk drives, but SCSI support is right around the corner! This is exciting news, and I am stoked that SMART support is finally becoming a reality!!!!
$ read more →Encrypting data with the FUSE encryption module
I use a laptop to conduct most of system administration duties, and periodically need to store sensitive information in my home directory on my laptop. To ensure that this information can't be used for malicious purposes, I use the FUSE encryption module to encrypt anything I think is sensitive (I probably go overboard when it comes to encrypting data, but you can never be too safe with your (or your companies) data!). Now you may be asking yourself why not GNUPG? Well, the FUSE encryption module allows transparent access to file and directories, so you don't have to manually key in a symmetric key each time you need to access a file (you only need to type the key in when you mount the encrypted folder)…
$ read more →Generating statistics from the Sun directory server access logs
I have been managing Sun's directory server for close to four years, and it is one of the few products I use that has all the bells and whistles out of the box. One extremely useful feature is the ability to generate statistics from the server access logs. This capability is built into the logconv.pl perl script, which is part of the Sun directory server resource kit (as a side note, logconv.pl is what motivated me to write ldap-stats.pl to analyze OpenLDAP log files). To use the logconv.pl statistics program to analyze your server access logs, you will first need to grab the resource kit from the Sun download page…
$ read more →Debugging apache article
If you subscribe to SysAdmin magazine, you might be interested in my article Debugging Apache Web Server Problems, which is available in the July issue. Here is the list of topics I covered in the article: Using single process mode to isolate problems. Using httpd flags to debug configuration errors. Debugging CGI script execution problems with ScriptLog…
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