Sidebar Sidebar
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

MacPro Raid Suggestion/Commenets/Questions

h1kar1

h1kar1

macrumors regular
Original poster
Jul 12, 2007
218
0
Los angeles
good day guys.

Was woundering if i can pick your guys brains a bit.

I have just got my dual 2.8 quad core MacPro

I am deciding how and if to do a raid on it.

apples website says it can do 0,1,5,0+1 but that its software raid
http://www.apple.com/macpro/technology/storage.html

Now to my understanding never used software raid before.
This will use my cpu more to do the the striping and what not.

I was leaning twords raid5 but not sure any more.

Any how suggetions comment

Right now i have 4 drives in there
320g that came with it
and 3 500g 7200 drives that i had in a nas laying around

A few questions.

1. Has anyone used Software Raid5? whats your thoughts on it? is it worth it with the speed decrees and the extra load on the cpu?

2. Is it better just to get some raptor drives for my OS drive and do either a 0 or 0+1 fact that raptors are only at 150gig kinda get me.

3. i have not install vista on this machine but do plan to once i get a 64bit version. Once i setup a Raid5 will i be able to boot camp and format a ntfs for vista? I've gone though the process on my laptop ie boot camping but does it work the same once you have the raid setup?

I am really torn here.
The MacPro does everything for me at home from the occatinal COD4 on vista to media streaming tons of movies and music to encoding video and email. I do the majority of my work from my laptop but do most of my numbercrunch proccess on that mashine

any comments or suggestions would be great.
 
You can't do a software RAID5 on OS X. You can only achieve a RAID5 by means of a hardware RAID controller card.

Apple said:
For the ultimate in data protection and enhanced performance, add the optional Mac Pro RAID Card with 256MB of RAID cache, a 72-hour cache-protecting battery, and hardware RAID levels 0, 1, 5, and 0+1.
Click to expand...
 
humm thats what i thought maybe i miss read the mac site.

Well what confused me i guess is that fact there talking SATA raid 5

Raid card is SAS

so figured they were stating the raid5 can be done in software.
Which to me seems like a step backwards in speed.
 
The way your Mac sees your drives are bay 1 as your boot drive, and bays 2, 3 and 4 are seen as one big drive number 2. If you look at the build screen for a Mac Pro at Apple's site, you'll see a nice $800 option to add a RAID card.

You could look into a external RAID enclosure, and slide your 2nd, 3rd, and 4th drives into. I love my Drobo. That could be an option too.........
 
The Apple RAID card does support both SATA and SAS drives, but all drives have to be the same type.

Unfortunately it does not support Bootcamp at all. You can't even exclude a drive from the RAID and use it just for Windows - it won't boot.

The CalDigit RAID card may be a better bet, but they're not available in retail yet.
 
Virtuoso said:
The CalDigit RAID card may be a better bet, but they're not available in retail yet.
Click to expand...

But with this card you lose the ability to raid mac pro's internal disks. And you have to buy external enclosure and extra disks.
I'm still preferring the apple card to manage the four hdds i have in my mac pro and eventually buy this to extend later.

EDIT: ok i'm an idiot. This card can manage internal mac pro's disks. Is sas ready?
 
I used western digital 250gig w16 drives. They're not the fastest on the block, and they were released 2 years ago, but trust me, they get the job done. They were on sale for $60 a piece from a discount store in KC that had bought out a bunch of CompUSA inventory. (sidenote: For fun, I bought a heatsink to overclock my router at the same sale, see this guide: http://guides.rackload.com/WRT54g-overclock/)

I reinstalled leopard 5 times to figure out the setup that was fastest. I settled on RAID0 with 16kb stripes. This gives me 1TB of space, and OSX boots from bong to quicksilver fully loaded in about 15-18 seconds.

Your mileage will vary. I would experiment with the stripe size and raid configurations until you are comfortable with the speed and redundancy.

I noticed the smaller stripe sizes booted OSX faster, but large sequential transfers (like 4gb dvd images) were slowed a tiny bit. I sprung for a faster system in general and experimented with the stripe sizes in RAID0 and settled on the smallest possible. However, with different drives/cache sizes/seek times, you will get different results.

These WD drives aren't the fastest in the world. If you have the cash, I would suggest Seagate 7200.11 drives. However, they are whisper quiet, my system is quieter with 4 drives than the clunky 7200.10 that came with this machine.

It's totally worth the effort and money. Good luck!
 
I have setup my Mac Pro system (3 HDs -- stock 250gb, and two WD Caviar 500GB)

Running a RAID-0 with the two Caviar 500GB disks, using this RAID Array as my boot volume. I realize it's risky, because it doubles the risk of losing data since one drive goes, it all goes....BUT -- I have to admit, so far, it's abolutely awesome. Above 75% faster performance, apps load almost instantly. It's a much better performance improvement as I see it, than even upgrading the processor.

This RAID0 system is fast, I am just using the disk utility to do a software RAID here. So, that's what I would recommend.
 
You may lose space in a RAID for parity (if you use 5 and 6?), this space is filled with data that can rebuild a drive or two (depending on the RAID) if it fails.

In a RAID where striping is done, data is split up - half on one disk, half on the other to decrease the total read time (to put simply). The danger here is the if one disk fails, you lose all the data as one half is useless without the other.

I highly recommend RAID 5 or 6, striping can be dangerous, especially if you are using old disks. Personally i think 0+1 is overkill, but I've never had anything that valuable to store.

Please correct me if i've gone wrong somewhere, it's been a while since I've looked at RAID
 
for 0+1 (or mirroring over stripes) you do not need a card. You simply set up two striped arrays and then mirror them. I tested this before switching to just plain raid 0. 0+1 gave slightly better performance than 1+0 (striping over mirrored sets) with software raid in OSX.

raid 5 you will need a card. OSX does not have drivers or software that allows you to create or run a RAID5 in software.

RAID 5 is like raid 0 where data is striped across disks, except that it computes parity for every transaction and distributed the parity amongst the disks. Parity is a XOR (exclusive or) of the data being written. Wikipedia is your friend if you want to get into boolean logic. You can lose any single drive at a time and you're OK, but the recovery process will put strain on the other disks while it recomputes your data (Several hour process) from parity across the other drives and may cause them to fail too.

Honestly, RAID0 is just fine for a casual user if you're using Time Machine. My 4 drive array theoretically have 4x the failure rate of any single drive, but I make daily backups to an external drive so you don't see me sweat it. You gain about 30%-50% more performance over 0+1 or 1+0.

If you're writing thesis papers or anything super duper critical, I wouldn't use RAID0, I would save them to a flash drive though. Murphy's law can suck. But for day to day stuff where I wouldn't cry if I lost my last 4 hours of internet browsing or games or a downloads or whatnot, RAID0 will turn your machine into the beast it was cut out for.
 
0+1 With 4 TB Drives

I've got 4 TB drives with Apple's RAID Card and a setup of 0+1. Although I encountered a few bumps at the beginning in just getting it set up, it has been smooth sailing since. Extremely fast and if anything goes wrong with a drive, I'll be able to rebuild. Throw 16 GB of RAM into the mix and I feel like I have the ultimate machine! I received a DUD off the bat but the second one has been flawless. Also, I ran updates yesterday and now notice the machine finally sleeps! 0+1 is extremely fast and efficient. Good Luck.
 
You must log in or register to reply here.
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.
Top Bottom
Back