Configuring Ubuntu – Part 1

Once I had Ubuntu Server 6.06.1 installed on my new web server, I quickly realized it needed several changes before I could put it online. Hence, this is the first installment in a series of blog entries to help others configure their systems.

If you installed from a CD-ROM and have a working network connection to your Ubuntu system, you should update the sources.list file used by apt-get so that your system won’t prompt you to insert the Ubuntu CD-ROM each time you install a new package:

1. Log in to your system via the console.
2. Run the following command: sudo vi /etc/apt/sources.list
3. Add a # before the following line (use cursor keys to put cursor in front of the line and then press i, followed by #) :

deb cdrom:[Ubuntu-Server 6.06.1 _Dapper … restricted

4. Save sources.list by pressing ‘Esc’, followed by the following sequence of characters to write the file and exit: :wq

Continue reading “Configuring Ubuntu – Part 1”

Bye Old Server. Hello New Server.

My web server was down for most of yesterday, for reasons out of my control.

I shelled in only to see one error message upon restarting the Apache web service: Segmentation fault. I checked the last few lines of Apache’s error_log only to see many more errors related to the same problem. It’s one of most dreaded messages one can receive on a Linux box, aside from the dreaded ‘kernel panic’.

A segmentation fault usually means one of two things in the Linux world: a software fault or a hardware fault. So, I set out to determine what the underlying cause was.

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Some Memory and CPU Benchmarks

Last weekend, I decided to test the memory performance of my ASRock 775Dual-VSTA motherboard paired with the Mushkin EM2 1 GB DDR2-667 memory kit.

Specifically, I was eager to determine the maximum memory bandwidth I could attain using DDR2-553 memory timings (4-4-4-12 stock), while acknowledging that the ASRock 775Dual-VSTA performs poorly with the standard DDR2-667 memory timings (5-5-5-12 stock). Hence, all tests below were completed with the memory timings set to DDR2-533. EVEREST Ultimate Edition 2006 was the benchmark utility of choice. CPU used: Intel Core 2 Duo E6400 (stock configuration with Arctic Cooling Freezer 7 Pro HSF).

Test 1 (CL-tRCD-tRP-tRAS):
4-4-4-12, CR: 2T
Memory Bandwidth (Read): 10,136 MB/s

Test 2:
3-3-3-8, CR: 2T
Memory Bandwidth (Read): 11,274 MB/s

Test 3:
3-3-3-8, CR: 1T
Memory Bandwidth (Read): 11,785 MB/s

Surprisingly, the Mushkin memory kit ran using a command rate of 1T using DDR2-533 timings! In contrast, I could only squeeze about 9.9 GB/s of bandwidth using DDR2-667 stock timings.

Continue reading “Some Memory and CPU Benchmarks”