Server Musical Chairs

Tuesday, April 18, 2006, at 01:29PM

By Eric Richardson

I'm planning on moving servers this evening, so if something seems funky you can likely blame that. This is a bit of an intricate move even though nothing's leaving my apartment, but in the end it'll greatly simplify the way I host this stuff. In the end, though, it's not as ugly as the configuration I once used to serve this site (October 2004).

Basically right now I've got an ancient PIII 500 up in the ceiling as a server. It's slow on the dynamic stuff, so all blog URLs are proxied through to my faster desktop (err... is it a desktop is it's actually supporting the desk?). The server in the ceiling also does NAT for the apartment network and acts as internal media server.

Now I've got some new guts to replace the server in the ceiling. Doing so with minimal downtime looks to involve a musical chairs of four distinct machines.

Drive Swapping

The current server (bit) has two IDE drives in it -- one 250gig and one 3.4gig (different eras, obviously). Combined they have about 180gig of live data, most of which is for internal apartment purposes only.

My desktop (sark) has three drives in it -- two 18gig SCSI drives and a 250gig IDE. The big drive doesn't really have much of its own on it; it's mostly just a mirror of the 250gig in the server.

Elsewhere in the apartment I've got three drives sitting free -- one brand-new 250gig IDE drive, one 18gig SCSI and one 80gig IDE.

The plan is for the new server (bit again? Not sure) to take two of the 250gig drives (the new one and the one from sark) and run them with software RAID-1.

Then sark will get three 18-gig SCSI drives (since it's the only thing I've got with a SCSI controller in it). Once it's not doing anything external I'll be wiping it and reinstalling to use two of these as RAID-1. The other will probably sit in as a MySQL backup or something like that. Then I guess I'll stick the 80gig drive in here as scratch space.

That accounts for everything but the 3.4gig drive, which may just go ahead and sit this one out.

Musical Chairs

Basic steps in the upgrade:

  • Copy blog content/software to my laptop (flynn)
  • Use flynn as temporary dynamic content server
  • Power down sark
  • Remove 250gig drive
  • Install drives into new server
  • Install Linux, Apache, etc on new server
  • Copy content to new server from bit and flynn
  • Unplug bit's ethernet and drop in new server as replacement
  • Bring bit down out of the ceiling
  • Shut down both bit and the new server (a little bit of downtime here)
  • Swap guts between servers
  • Replace new server in the ceiling
  • Bring the new server back up
  • Install less critical services on new server (like email)

Yikes. That sounds way too confusing just writing it.

Update (6:25pm): I realized walking home that I forgot the 250gig drive in the current server. 3 drives for 375gig RAID-1?