Monthly Archives: March 2006

Another upgrade

This weekend I’m going to attempt another hardware upgrade.

The main mail server for midrange.com (rivendell) is showing it’s age … mind you, it’s still performing fine, but it’s pretty loud and it’s maintenance contract expired last month. A new contract would have costed $300, while a new server only cost $600.

So I got a new Dell PowerEdge SC430 (Pentium D, 3ghz, dual core, 1gb ram, 80gb DASD) to replace the current Dell PowerEdge SC600.

My plan is to backup the drives (mirrored pair) to a USB hard drive and then transplant the drives into the new server.

The only hitch is that the new server primarily runs on SATA, while my current drives are PATA. This I’m solving by getting an add-on ATA/133 card. I’ll set the system to boot off of the drives on the add-on card and use the SATA drive as swap space and a backup drive.

In the past, this kind of hardware upgrade went very smoothly. Mainly because Linux was able to detect the changed hardware and reconfigure itself appropriately. This is why I upgraded rivendell to Fedora Core 4. Redhat 8 would not have been able to deal with the new hardware.

Keep your fingers crossed.


Update 3/25 @ 3pm

Looks like the upgrade was a success!

There were a few minor glitches with the file system table (fstab) … since I put the main drives on the ATA/133 adapter card, they changed from being /dev/hda to /dev/hdc. I had to twiddle with the config to get it to boot properly.

And, in case you’re wondering, I did back it up to the USB drive. That took a bit of doing though, because the USB ports on the old system are ‘full’ speed (10mps). I had to put the USB drive on gondor and do the backup via the network in order to get it done in a reasonable amount of time.

[tags]Linux, Fedora, Dell, Poweredge, Upgrade[/tags]

Greylisting

For a while I’ve been using limited greylisting on my mail server with reasonably good success.

Last weekend I implemented site wide and I have to say the results are dramatic. The amount of spam (even low rated by spamassassin) has dropped off significantly.

Detailed information on greylisting can be found here, but in a nutshell:

Greylisting relies on the fact that spammers don’t use normal mail servers. Basically, the first time a mail server receives a mail delivery request, it responds with a soft failure … with a message indicating that greylisting is in effect and they should retry the delivery in certain amount of time (this is a human readable message, not machine readable). Since normal mail servers will accept this message and requeue the email for delivery, the email will then be delivered normally (probably on the next pass).

Spammers aren’t that persistent, so they just go on to their next target.

A good greylisting implementation retains the list of servers that have successfully delivered in a whitelist, so the next time they try to deliver there is no delay, the delay is only encountered once.

One downside of greylisting that I’ve found is that there is an increased chance of messages arriving out of order when a server tries it’s first message deliver. The reason is this … the first message delivery will be attempted and be rejected due to greylisting, if a different message delivery is attempted AFTER the greylisting delay has expired but BEFORE the first message is delivered, then the second message will be delivered and will be out of context.

I’ve got my mail server configured to greylist servers for only 2 minutes … so the next time the server tries to deliver, it’s almost certain to be successful.

I’m using milter-greylist with sendmail. It was easy to setup and works great.

[tags]spam, sendmail, greylisting, milter[/tags]

Dead TiVo’s Aren’t Much Fun

Well, our TiVo started to die.

For a few months it’s been locking up on us … didn’t seem to mater what it was trying to do. Record, playback, or just sit idle.

While we were on vacation, the Linksys WRT54G wireless router got screwed up … so the Tivo wasn’t able to download any new program info. Thus, it ran out of data.

When I got back and reconfigured the router (not sure why the router got screwed up in the first place), the Tivo tried to download 2 weeks worth of data.

Unforunately, it kept locking up when it was trying to process the downloaded data.

I figured it must be some corrupt data … so I decided to reset the entire thing and have it reload from scratch.

I ran the reset … and it locked up a few times when trying to download the data again.

Even after it was able to download the data, it kept locking up.

I called TiVo and they said it was probably dieing … and offered me an exchange. Exchanges cost $149. Oh well, better than buying a new unit and signing up for a new lifetime subscription (which, btw, is going away soon).

I opted for the advance exchange … where they send me the new unit before I send the old one in. Standard deal … they charge the credit card for the new unit and the cost of the old one … and issue a credit when the old unit arrives.

Got my RMA and waited for the new unit to arrive.

Yesterday, the new unit arrived. Same basic unit, except it doesn’t have the front panel buttons (which I kind of liked).

It took a while to get it configured, because it had a much older version of the OS pre-installed … and I thought my only option was to use the phone. We don’t have a phone line near the TiVo, so I had to use the wireless phone jack. It has a lot of static on the line, so the connection was much slower.

Eventually it finished the setup and we were off and running.

Now we just have to setup all our Season Passes and favorites again.

Luckily we had the snapstream so at least we could time shift our viewing.

[tags]Tivo, TV, Television[/tags]