Welcome to the MacNN Forums.

ginop1 · May 12, 2004, 12:20 PM

I have a PowerMac G4 500 (Sawtooth). I am looking for an RAID unit. I would like the RAID unit to be external. Do I need a PCI card for the RAID unit? What software do I need to set up the RAID, if any, or will Mac OS X recognize it immediately? Anything else you can tell me that I did not think to ask will be appreciated.

OreoCookie · May 12, 2004, 10:50 PM

Well, you can get a SCSI RAID for instance, so you need a SCSI card with an external (fast) connection. Then you buy an external SCSI RAID, the cheap ones use ATA drives internally (sufficient for lots of stuff) and from the PowerMac side it looks like a `normal' SCSI harddrive.

Then -- if you are willing to spend more money -- you could get a SCSI RAID with SCSI drives which are faster for databases and other stuff (non-contiguous data), because the seek times of most SCSI drives are faster (except for the Western Digital SerialATA Raptor drives that also spin at 10 k).

On the top of the ATA drive options (that you can probably afford) is an XServe, but I'm not sure if there are Fibre Channel adapters for PCI64 with Mac drivers.

I'm not sure what you are planning to do, but probably, you don't even need an external RAID. What do you want to do with it and why do you need a RAID. I mean, your machine seems to be rather old ...

ginop1 · May 13, 2004, 10:34 AM

I'm not sure what you are planning to do, but probably, you don't even need an external RAID. What do you want to do with it and why do you need a RAID. I mean, your machine seems to be rather old ... [/B]

Well, basically I want a RAID so that I always have a backup of my extensive mp3/ AAC collection. And with the larger disk size that a RAID offers, it would be nice to re-rip some of my CDS using Apple's lossless codec, which produces large files. I would also like to start building a videoo library with the larger disk size thata RAID offers.

dreilly1 · May 13, 2004, 11:11 AM

Here's an easy way to do RAID: get an external firewire drive bay that can hold two drives. I found one on eBay for $80 or so.

Then buy two Inexpensive Disks (preferably identical models), and put them into the firewire drive bay as a Redundant Array just like you'd install a Master and Slave drive into a single ATA channel in a computer.

Then plug the whole thing into your Mac. OS X can do software RAID pretty easily through the Disk Utility, although I don't remember the specifics on how to set it up. Basically, though, you have two choices:
- RAID mirroring will store the same data on both drives. You will only get half as much space and slightly slower drive access than you would have if you kept the two drives separate, but if one drive dies, you have the other as a built-in backup.
- RAID striping will use both disks to store the data in parallel. You will get as much space and much faster drive access than you would if you had kept the two drives separate, but if one drive dies, then all your data is gone.

Either type of RAID will be slower than if you got a dedicated hardware RAID setup, but those will be more expensive.

RAID mirroring seems overkill for music and video on demand, you can easily replace the information if a drive dies (especially since you only rip from CD's and DVD's you own, since you knoe that if you pirate it makes Baby Jesus cry.) But RAID striping could help, because it gives you faster access for all this bandwidth-intensive stuff.

For the record, I put together my RAID mostly to see if I could, but I plan on eventually getting a DV camera, and the RAID striping will come in handy for video editing...

OreoCookie · May 13, 2004, 06:30 PM

Yes, the suggestions above has some truth to it. I'm not sure if you have an idea how much RAIDs are. We're talking $x000, where x>=5 (usually). If you buy a used one, the capacity isn't at all that great.

So if I were you, I'd get two 160 GB drives that currently offer the best bang for the buck. If you have space internally, buy a host adapter and put them inside your PowerMac. If you don't, then buy external FireWire enclosures.

MacOS X can create a software RAID. Since you want to back up your files, do not select striping but mirroring. I don't think, you have more than 160 gigs of music anyway.