Server backups, Time Machine, best practices

Question

Hey guys, I've got a Mac Mini running Lion Server that is providing VPN, Profile Manager, and some file sharing to macs and i-devices in my household.  I also am using portable home folders for the kids accounts. (and soon I may be doing the same for my account and the wife's account)  Connected to my Mini is a Drobo. 
Currently I'm using Crashplan to backup data on all of our client machines.  (an iMac, and a couple of macbooks)  However, I would like to add Time Machine to the mix.  Here are my thoughts:
client machines:
- use TM to backup to the mac mini server.  (backups stored on drobo)
- EXCLUDE the 'local' (sync'd) home folders for network users, since their home folders are actually stored on the server. 
server:
- use TM locally on the server to backup itself to a separate external disk.
- this backup should INCLUDE the users home folders since they're not getting backed-up on the client side. 
- optionally install crashplan on the server and use it to backup users' folders as well??
The whole goal here is convenience.  I trust Crashplan to backup my important stuff offsite (pictures, videos, etc), but in the event of a disk failure I want an easy, no-hassle way to fully restore a machine - either client or server machine - back to its original state before the disk failure.  The only thing that has me scratching my head a bit is the user folder stuff.  If everyone had local accounts it would be easy - just use TM to backup everything.  But since the home folders (for the network users) are actually stored on the server, with a syncronized version on the client, it complicates things a bit.
Love to hear anyone's feedback on how to proceed.  Thanks!

Answer 1

It certainly sounds like a solid plan, you're correct in that it doesn't make sense to backup the Home folders for network users, since those are on the Server, and in fact you might be able to get by without TM by considering the local Macs themselves the backups of the home folder, the odds of losing both are highly unlikely, except by some sort of proximity event, like a burglary or house fire (knock on wood).  In that way, I would actually say cloud storage would be better, but again, I would be satisfied with just the "backups" being the local machines themselves, and you're going that extra mile by backing said Home folders via TM (I'm assuming via a Time Capsule or external hard drive?).
Since the goal is convenience, you may also consider adding a second drive to your Mac Mini, assuming it doesn't already have one.  Currently, I'm using RAID1 (mirroring) with two hard drives in my Mac Mini, so should a hard drive fail, it will automatically boot from the second hard drive and let you know the first drive failed.  It's certainly cheaper than a Time Capsule, especially if you have the tech prowess to take apart your Mac Mini and install a second hard drive.  I purchased iFixit's kit for adding a second hard drive, and while the $50 cost wasn't ideal, it beat several hundred dollars for a Time Capsule, especially since I don't need Terabytes of storage and I happened to have a spare 500GB HDD laying around... That could be you, too!
As for the Home folders, again I would go the simple route and just use a RAID1 array in the Mac Mini, that way there's no need to backup the Home folders, they're already automatically backed up to the second hard drive with RAID1.
As you can tell, I like RAID, but also, if you go the RAID route, they say HDD read speeds increase (there's some conflict on the Internet it seems, but I believe it... I see around a 20MB/s speed boost, not a huge deal, but it's something).