I'd set aside this morning as time to deal with the server's questionable second hard drive.
Shut down workstation (it was overdue for a reboot anyway), then the server.
Find a SATA cable, and connect the new drive to the server's motherboard.
Boot the FreeDOS USB stick.
Get various error messages relating to a partition table, and no command prompt.
After much fiddling around, come to the conclusion that FreeDOS just doesn't work on this machine.
Boot Linux in single-user mode. Try to partition & format the new drive. Get confusing errors.
Fiddle around some more.
Shut down and open up the Windows machine in the lab. Connect the new drive as secondary. Try to figure out how to partition it under Windows. The device manager can find it, but can't populate the partition table. The disk partitioning & formatting utility doesn't see it at all.
Reboot using the USB stick, and at least get WDIDLE3 to find the drive and change the timeout from 8 seconds to 5 minutes, which ought to avoid the hard-parking wear-out problem for which the WD "Green" drives are notorious.
Plug the drive back into the server. Boot normally. Try to use the cool GUI tools to partition & format it (one big partition, ext4). Dead Rat Disk Utility can't create an ext4 partition, not can cfdisk. Gparted can, but Disk Utility tells me it's misaligned by 512 bytes and warns of a horrible performance hit (despite MiB alignment supposedly having been in effect). Fail to find any way to get it properly set up on the server, under Debian-squeeze.
Server off, again. Drive out. Server on. Plug drive into USB adapter, and thence into workstation (running Debian-wheezy). Format with, if memory serves, Disk Utility. Claims to be OK. Unplug; plug into server; poke with Disk Utility: no nasty messages this time.
Server off again. Move drive back to its SATA port. Boot single-user. Copy entire contents of old drive to new drive. Go do other stuff in the meantime. Come back every so often and watch the filenames spin by. Gosh, some of that stuff is old! Oughtta be archived on 9-track magtape. Eventually, it finishes!
Hit Control-D to get multi-user mode. Switch KVM back to workstation, and fire up the remote console. Wait, no user 'eric'? WTF?
Switch off DSL modem, just in case mail comes in and gets bounced on grounds of "no such user". Ponder a while. Make sure slapd is running: makes no difference.
Oh, well: reboot! Server comes up normally, near as I can tell. User "eric" is present now. Turn modem back on. Mail starts dribbling in.
The upside of having the server down for several hours: most of the spam servers don't do retries, and may decide I don't exist. For a while, anyway.
I guess I started the process around 0700, and got the server running normally again, and connected to the Internet, around 1350.
And now for the alarming news: that Windows machine in the lab is running low on disk space, and could maybe use a nice 320GB drive transplant or thereabouts. Think I can just copy Windows and the installed applications over to a new, bigger C: drive? Yeah, right. And Windows has never really played nice with "hey, let's put most of the stuff on D: instead!"
Well, maybe there's some utility out there for transplanting Windows installations....