• Published on | Nov 17, 2005 | by Chris Osborn

OpenMosix on heterogeneous junk?

For the last few weeks the spam load on one of my servers has gotten way way out of hand. The computer is averaging a load of 4-7 constantly. The number of sendmail processes that are running just drag the machine to a crawl. Over a year ago or more I changed sendmail around so that it has 4 queues and installed re-mqueue from Paul Pomes. This helped dramatically. Stuff that was sticking in the queue and dragging everything else down now gets automatically moved to queues that run far less often.

These days though just getting the spam into the first queue is dragging the machine down. It doesn't help that I run a secondary mail server which accepts connections and queues things up to relay to the primary. Spammers take advantage of the fact that the secondary can't do any real processing and dump tons and tons of mail on it for domains the primary server hosts, but is addressed to invalid recipients at those domains. If they had connected to the primary server it would have been able to check that the address exists before accepting the mail. So the secondary has tons of messages that it dumps onto the primary which the primary immediately bounces.

Last week I stumbled upon openMosix while searching for something or other unrelated. I'm wondering if this might help with the sendmail situation without having to buy newer, faster, expensive hardware when money is really tight right now.

I happen to have access to a lot of "junk" computers. Friends, family, people I do work for, etc. will upgrade their computers and give me the old ones. I take them just in case they might have some good parts in them for some project down the road. And when I say junk, well it's really close. I have a bunch of Mac 61xx class computers, lots of 486 and Pentium computers, and a couple of "modern" Pentium II computers. These things should be more than capable of running a couple of sendmail processes at a time.

What I'm wondering is can I mix&match the Macs and PCs and have it work? Also, how much of an install do I need? Can I just have a kernel, init, and busybox on most of the computers, or will I need a fairly complete install which includes sendmail? These things weren't mentioned in the FAQ and I haven't dug any deeper yet since this idea just popped into my head.

I'm not sure how far I will take this. It's a lot of work doing a Linux install from scratch, esp. on those old Macs. Although after I've done it I might be able to do some kind of disk mirroring to get the rest going. I'm also concerned that the increase in the electrical bill will probably also make it a waste. I need to get one of those little power meter things that tell you how much electricity is being used. But of course those cost money too. :-)

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