new mac setup - suggestions, ideas? D2D2T etc

[derek500]

I'm looking at updating/upgrading one of my Retrospect systems and wanted to run this config past you folks. Right now the system has a LVD SCSI AIT-2 drive and runs Backup Server watching our network for laptops, and backs up to tape. I have it set to back up every machine every 3 days. We cycle the backup set every two weeks, with 6 tape sets in rotation, so we have 12 weeks of backup at any given time. I would like to do the back up to disk instead of tape, but we are still required to do the set rotation, so I was thinking of this solution:

 

Configure a new PowerMac with some additional RAM (the lowest cost is a dual 2 GHz G5; that with 1 GB of ram should be more than enough machine), then I can re-use the SCSI card and tape drive from the old system (it's an ATTO UL3S, please speak up if that won't work in the new PowerMacs). Then I install the OS and Retrospect on the primary drive (160 GB internal drive). For the backup storage, I'm thinking I can install myself two 400 GB internal SATA hard drives and use Disk Utility to create a RAID 0 800 GB storage area. Once every other week, dump the backup to tape and take the tapes offsite and recycle the disk space. The two week backup sets tend to run about 120 GB, not quite filling two AIT-2 tapes.

 

Any thoughts on this? Things I'm interested in...

 

Hard Drive Cache:

I see a lot of different cache sizes available. If I remember right, Retrospect really doesn't want any cache at all, right? So is this irrelevant? How do I ensure that the cache isn't used?

 

RPMs:

7200 seems sufficient, especially with a RAID 0 in effect? Is it worth 10,000 RPM drives?

 

Tape Speed and Capacity:

I'm going to have to do the offload to tape manually (right?), so it would be nice to have happen as fast as possible. I could probably spring for the AIT-3 drive if there's a significant speed gain, but otherwise I'd rather not spend it if I don't need to.

 

Disk to Disk to Tape:

I've got plenty of experience making backup sets on disk, and making backup sets on tape, but I've never moved a backup set from one to the other. Is that the duplicate function? What is the best approach for this? Backup to File? Backup to Disk? Can a File span multiple volumes if needed?

 

Physical storage:

Is it possible to have 3 internal hard drives in a powermac G5? Am I wasting my time installing internal disks? Is this all doable using external firewire drives? It seems to me that using internal drives will cost less than externals (no enclosures needed) and by directly connecting with SATA will be faster, more reliable, etc. The drives would be controllable by disk utility and I could RAID them, etc. That part of the idea sounds difficult to do with external drives...

 

...

 

Ideally I would try this stuff out to see how it goes, but I don't really have the available systems or time to play with. Any thoughts would be appreciated. I'm hoping the Disk to Tape part is as easy as it sounds. Any thoughts are much appreciated.

 

Thanks,

 

-Derek Cunningham

[unclebexscz]

Your plan sounds like a good idea, but (without checking) I think I remember Macs only having room on the inside for 2 hard drives. Hopefully I'm wrong though (I'm not a Mac guy).

 

This might only matter if you don't have enough hard drive mounts inside the case... if you are considering 10K rpm drives then you might also want to think about taking advantage of Firewire 800 being offered on the latest Macs. It might be a good place to build in some additional capacity into your backup server.

 

I've been using tape as my primary backup for quite a while, but I do a proactive backup to 7200 rpm firewire attached drives so that I can do quick recoveries of those "stupid little mistakes" that people make when they delete something off of their computer or the highly used portions of our server.

 

Additionally, if make sure that you read up in the forums about people's disk-to-tape experiences with Retrospect. It seems to be quite the conversation piece these days. Too many people tempted by cheap disk prices and wonderful throughput when compared to a pure tape setup.