Sometimes after a fresh Debian Etch install  (I am not sure if this is fixed yet in Lenny or not), the order of your ethernet interfaces will be incorrect. You may also be in a position where you have more then two NIC cards and and you wish to swap eth0 and eth1 with eth2 and eth3, for consistency purposes for example.

In order to do so, you’ll need to make a change to the udev configuration file which controls which interfaces receive which names. You need to edit the following file:

‘/etc/udev/rules.d/z25_persistent-net.rules’

Simply make sure that you match the proposed interface with the correct MAC address and you are all set.

Go ahead and restart the server and you should be all set with the correctly labeled interfaces.

While doing research into poor write performance with Oracle I discovered that the server was using the LSI SAS1068E. We had a RAID1 setup with 300GB 10K RPM SAS drives. Google provided some possible insight into why we the write performance was so bad(1 2). The main problem with this card is that there is no  battery backed write cache. This means that the write-cache is disabled by default. I was able to turn on the write cache using the LSI utility.

This change however did not seem to any difference on performance.  At this point I came to the conclusion that the card itself is the blame.  I believe  that this is an inexpensive RAID card that is good for general use of RAID0 and Raid1, however for anything were write throughput is important, it might be better the spring for a something a little bit more expensive.

When it was all said and done we ended up replacing all the these LSI cards with Dell Perc 6i cards.  These cards did come battery backed…which allowed us to then enable the write cache, needless to say the performance improved significantly.

I recently needed to acquire the Dell service tag number of a remote linux server. The method I used to do so was simple. I used the following command:

‘dmidecode -s system-serial-number’

Depending on your system, you may be able to obtain the following information using ‘dmidecode -s’:

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