I'm debating between building an unRAID server or suping up my Mac Pro with a RAID Card and going with RAID 5. I feel the need for data redundancy, having lost 3 hard drives in the past 2 months.

I was dead set on unRAID until I read a review on (http://www.barefeats.com/hard104.html) barefeats (http://www.barefeats.com/hard104.html) about these new sub-$250 RAID cards for the Mac Pro. That, and the fact that I already have 3 identical 500gb hard drive (spinpoints) and I live in India, where we have 7-8 hours of scheduled power outages, having 1 less box to run is a GOOD idea (I run on batteries during the outages - batteries are already wearing out).

I have a few questions remaining:

Will it work to have a 5th, non-RAID SATA drive (from the sata ports on the logic board) in the second optical drive bay for XP, and then boot OS X from the 4-disk RAID 5 array? Windows doesn't even need to know the RAID is there, as long as boot camp can see both.

Will a hardware RAID 5 be faster?

There is no good solution for copying data from my existing drives to the RAID where the RAID is using the same drives? I have 700GB of movie files and 100GB on my OS X Volume (apps, photo, music, family videos etc). Am I right in thinking I can build the RAID 5 from 3 drives, copy the data from the 4th drive, and then incorporate that 4th drive into the array as the parity drive?

No problems with network Macs reading/streaming data from the RAID array as long as the Mac Pro is on, right? It's always on - my download machine and Skype phone service.

The plus sides of unRAID are that it's WAY way way more expandable. I figure the RAID solution will give me 18-24 months of library expansion (till I hit 1.3TB of data/archive media) and by then 1TB drives should be around $100 each.

The RAID card is, of course, cheaper up front, $250ish for the card and $90 or so for the 4th drive and I'm up and running.

Other factors I'm not thinking about?

Oh yes, I put in this forum because the Mac Pro will likely be my main HTPC as well, but I'll be streaming from it to other Airport Expresses, even an iPhone, MBP, and maybe an AppleTV.

How important is the data you want to store on your RAID? Is it "irreplaceable" or would it just be inconvenient for you if you lost it?

The reason I ask is there is a filesystem called ZFS available for OS X. I'd call it Alpha or perhaps Beta quality. It doesn't implement RAID-5 but something similar called RAIDZ. And it's free, so you could save yourself the cost of a RAID controller card.

Check it out here. (http://zfs.macosforge.org/trac/wiki/)

The filesystem is very stable, production quality, under Solaris, but you would need to run another computer for that. Or perhaps run Solaris under VMWare Fusion, but I'm not sure how well that would work. Also if you do go for another computer make sure it is 64-bit architecture.

Read the Wikipedia entry on ZFS (http://en.wikipedia.org/wiki/ZFS) for more details.

I don't know what RAID card you have spec'd out, but many non-Apple RAID cards won't support booting OS X on RAID 5.

Thanks guys. I've read about ZFS - excited for Snow Leopard to incorporate it, but I'm not a command line guy any more and I'm actually looking for my data to be secure, which has me second-guessing everything, really.

I have 100gb OS X and docs and photos, music etc, and 30gb or so in my XP partition, and then I have around 700gb of media files, which I'd prefer to not re-acquire. I'm running a 120gb boot camp drive in the second optical bay of my Mac Pro to give me some backup of my system volume, but everything else is unprotected - and needs to be protected.

The RAID card I'm looking at is the RocketRaid 2640X4 for $150. I'm thinking I could use my 250gb (factory original) sata drive for both OSs, and then a RAID 5 of 4x500gb (I already own 3 identical drives) for a 1.3TB data pool - and use that to also provide Time Machine backup to my system drive plus 1.2TB of other data. Could consider a second 250gb drive to run RAID 1 on the boot drive - although I think software RAID would actually be slower?

The great downside (vs unRAID) of course is that it's expensive to expand. Take out all 500GB drives and put in 4x1TB drives after 2 years. And tricky to move the data around.

Performance isn't a huge deal for me. The Mac Pro is fast enough for me - don't do Pro editing- just mundane tasks day to day in OS X and then I game on it in Widows.

Thanks for the feedback - more would be appreciated!

Nightfly,

I just built an 8 drive RAID 5 using the Rocket Point 2322. I tell you, the case is a screamer, and we got a heck of a deal at SATAsite (http://www.satasite.com/sr-hd-pro-enclosure-with-card.htm). 2.5k for the enclosure, the RR card, and 8 1TB Hitachi's. It screams at about .5GB/sec! All you RAID searchers should take a look.

So I have a bit of advice for you. The RR cards are great values, but they have some downsides. The first of which I couldn't verify if the 2640x4 could boot OS X, as the pdf manual was corrupt. Though the manual for the 2322 didn't confirm nor deny if that card would boot OS X either. So I would email RR with the question, unless you can verify it somewhere.

Other than that, the case when it arrived had some loose connections, so it had to be disassembled and all connections reseated to get a few drives to mount.

The card has a web GUI, and you need to download the manual and pay attention. It took us a call to RR to get the procedure down, as the manual left out a few key steps, like having to use Drive Utility to initialize the RAID after the drives had been set up and the RAID built using the web GUI. Fortunately the RR support guy was spot on and had obviously dealt with setup issues on the Mac many times.

Also, the RR cards have a separate support site (http://www.hptmac.com/US/product.php?_index=45&viewtype=download) for Macs that isn't really obvious from their regular web page.

So my advice would be to run two separate boot volumes for XP and OS X, and build a 3 drive RAID 5 internally. Then I would get an external drive and backup your boot volumes. You don't need any more speed on your boot volume, but you'll appreciate it on the RAID. And if you need a bit more space in the future, you can get an external case to match, and easily expand a drive at a time.

One last point, and that is that there is a spec sheet for drive compatibility with the RR drives. You might want to check that out. It's linked to off of the 4604x4 page I linked you to above.

Good luck