backup strategy/location holding disk

Ok, I've subscribed to the list and have started wading through the infoand archives. Seems I never quite find the info most applicable to whatI seek. I've been using afio but people have recommended to try amanda,so I'm looking at it.


I've got two cobalt raqs that use a form of Redhat 6.2 as o.s.

They each have a pair of 40 gig hard drives in raid 1 config. I have aQuantum DLT 40/80. One raq is a web/email server, the other a file sharefor a small business with about 10 users at present. (Low volume.) Thetape drive is plugged into a scsi port on a raq. I also have an old Dellserver with I think a 9.1 Gb scsi harddrive in it that isn't doing much.

Right now I only have about 6 tapes but plan on seeing if I can talk themanager into another 10 at least. We need to keep a full backup offsite.

The amount of data generated per day is quite small here- probablybarely a few megs. It may grow as we add to our wan, but now it is justabout 10 users.


So a few questions:

I'm not clear on backup policies. I think a complete system backup wouldbe great so if I had a failure I wouldn't have to reinstall the variousprograms I've needed. But perhaps this is asking too much, I don't know.Maybe this is more the job for some kind of linux ghost? Do people justback up user generated data?

I've got 30 gigs free so far on both Raqs but that will shrink overtime. It would be plenty for now perhaps to set up a holding disk on.But as it fills, it would be too small for a system wide backup. Can'tadd another harddrive to the raqs. So there is that old Dell serversitting there. It doesn't have an exterior scsi port for the tape drive.I could add perhaps a big IDE hard drive to it (a big scsi drive is toocostly for this budget operation). Can Amanda, which I have installednow on the raq with the tape, use a 'client' or that Dell for a holdingdisk or does it make more sense to have the amanda server on thecomputer with the holding disk? Another option would be to buy a bigdisk for the old Dell and a scsi card for it so I can plug the tapemachine into it. But that is asking for a bit more money.

I did a quick seach of the archives about whether Amanda doesdifferential backups and didn't find much. Is it just incremental/full?I ask because in my limited knowledge it seems differential would be abit easier/safer to manage with low volume data stores.

I've found a couple excellant reference sites so hopefully they willanswer most config questions.


Thanks for any advice, I appreciate it.

--
Jim D.