Posts tagged with “freebsd”

Mon 23 Feb

Dell PowerEdge T300 SAS RAID and FreeBSD

I spent a couple hours tonight tackling this problem so I thought I'd post a solution here in case anyone else runs into it.

Scenario: Performed a clean install of FreeBSD7.1-RELEASE on a Dell PowerEdge T300 server with a SAS RAID controller, which completed without errors. After rebooting and beginning to install packages, I started seeing the following error: mpt0: QUEUE FULL EVENT: Bus 0x00 Target 0x00 Depth 120.

Solution: Searching online indicated that the problem was with support for Tagged Command Queuing in the mpt driver. The output of camcontrol was:

skipper# camcontrol tags da0 -v (pass0:mpt0:0:0:0): dev_openings  255 (pass0:mpt0:0:0:0): dev_active    0 (pass0:mpt0:0:0:0): devq_openings 255 (pass0:mpt0:0:0:0): devq_queued   0 (pass0:mpt0:0:0:0): held          0 (pass0:mpt0:0:0:0): mintags       2 (pass0:mpt0:0:0:0): maxtags       255

I then entered:

skipper# camcontrol tags da0 -N 119 (pass0:mpt0:0:0:0): dev_openings  119 (pass0:mpt0:0:0:0): dev_active    0 (pass0:mpt0:0:0:0): devq_openings 119 (pass0:mpt0:0:0:0): devq_queued   0 (pass0:mpt0:0:0:0): held          0 (pass0:mpt0:0:0:0): mintags       2 (pass0:mpt0:0:0:0): maxtags       255

This second command limited the size of the queue to 119, preventing the error I had seen before. To ensure that this problem wouldn't come up in the future, I added the following line to /etc/rc.local

# Set the devq_openings to 119 to prevent problems with SAS controller camcontrol tags da0 -N 119

Doing this runs the command at every boot, preventing the problem from creeping up in the future.

Additional Related Resources:,-freebsd-7.0-on-dell-1950-td20019090.html

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Fri 31 Oct

Halloween Geekiness

In a few hours darkness will descend over Chapel Hill and the Halloween revelries will begin. Instead of going out partying this year (since I've come to realize I just don't enjoy the party scene) I'm going to be volunteering with StudGov as a spotter. My understanding is that mostly means I will be helping drunk people back to their dorms and generally helping people stay safe. Hopefully my evening will be uneventful.

Last night I set up a new server in my apartment: It's a FreeBSD system running on some old hardware I had laying around (I mean old: Celeron 400 with 128mb RAM). I had tried putting Ubuntu on it in the past, but that was just a bad idea since it was far too slow to do anything interesting. Instead, I have it set up in my living room. I'm thinking of it as a long term "get better with UNIX" project.

My impetus for setting up forbin was actually because I'm going to be helping coach a FIRST robotics team for Durham Public Schools. My friend Maggie and I are the "programming mentors" for the team, and we will provide inspiration and guidance to the next generation of computer scientists.


Since the high school students who will be on team will have to be programming in C, I decided they should have easy access to a UNIX environment in which to write their code. Perhaps the FIRST robotics people will give everyone a nice IDE and everything to use to develop C on Windows, but in my experience it's much, much easier to write C in a UNIX environment than in Win32.