I support a number of developers. These developers all have Windows desktops, but need to edit their code which resides on UNIX hosts (AIX, Solaris, and Linux). I love Samba, but not if it’s installed on 300 UNIX hosts. It’s another software package that needs to be configured, firewalled, monitored, patched, and maintained. The permission model for Samba is somewhat orthogonal to the permission model for UNIX hosts, too, so my tools for handling user accounts won’t work. My developers want to edit their code with local GUI text editors. Getting them to use X11, or even text editors via SecureCRT is not a good solution, mainly because they resist. I’m cool with that. I know what tools I’m most …

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“I see they’ve got you doing everything around here now.” I was opening the janitor’s closet outside of my office. They have a nice sink in there that makes cleaning our fish tanks easier. My friend Eric was walking past as I was unpacking the closet. “Yeah. I guess I shouldn’t have been a smartass to my boss,” I said with a grin. “But seriously, why are you in the janitor’s closet?” “It makes maintaining the fish tank easier.” “Oooh, you guys have a fish tank?” “Yeah, come here and take a look.” Our cube farm has two tanks. One is in the middle, just as you walk in the door. It’s 55 gallons and has orange platys, green tiger …

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I noticed this morning that the RAID containers on my new Dell PowerEdge x9xx servers don’t have their caching options enabled. Now, I understand that write caching is potentially risky, and I understand why Dell ships the PERC 5/i controllers without write caching. However, no read caching? That doesn’t make much sense. While I was mucking around I did some benchmarking of the controllers with different cache settings. I used Red Hat Enterprise Linux 4 Update 4, running on a Dell PowerEdge 2950 with six 146 GB 10K SAS disks. The filesystem is a 20 GB ext3 volume created in LVM, mounted with data=writeback. I used bonnie++ to generate load, which for that tool means sequential writes and reads. Each …

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System administrators need a solid background in the fundamentals of operating systems. Unfortunately, good defaults and better tools mask the need for that until something breaks. On top of that there is very little recognition of the theory behind how operating systems work and its use in practical, day-to-day system administration. This morning my team was faced with a puzzling problem. A file system which had 34% free space was no longer allowing new files to be created in it, but pre-existing files were still being appended to? How does that work? The junior admin who was the first responder was puzzled. Could it be a permission problem? Maybe a reboot will fix it… Inodes are one of those things …

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