Raid 0 help!

[Texasmeat]

I am looking into setting up a raid 0 on my pm g5. What hardware do I need in order to do this? The guy at comp usa told me that I dont need a pci controller but apple's support site says I do need a pci controller. Anyone have first hand knowledge of this? Thanxdo

 

[coach_z]

in general i would go with the apple website over some guy at comp usa.

 

[warrenbert]

OSX has software raid built-in, so you could set up a RAID 0 array using Disk Utility. The major drawback is that you cannot boot off of your RAID array, meaning you must have a minimum of three disks (boot disk, 2xRAID disks).

So, since the G5 only has two disk connectors, you would indeed need an additional PCI Storage Controller. A basic controller card (either ATA or SATA) would let you use OSX software RAID. For maximum performance, you could get a card with a built in hardware RAID controller. That would let you boot from the array, but they will cost you at least $300 just for the card.

I'm not sure you can build a RAID array with individual external drives. There are aftermarket RAID enclosures that house more than one drive and connect through IEEE1394 ports (both 400 & 800). They are quite expensive and you would get better performance connceted directly to a PCI slot.

 

[Texasmeat]

...

Than Warren. This is what I was talking about. Things like this are not often easy to find on the net. i found numerous explanations of a raid setup and what it does etc. But the G5 raid is elusive on the net. At least for now. I was not aware that you could not boot from a raid array.

 

[Rebo0ot]

Cannot boot off RAID array

Do you think TIGER's release at the end of April will allow you to boot off of a RAID array? I have a Powermac G5 duel 1.8. I purchased a 2nd HDD and now have two Seagate 200gig SATA's. After reading this forum, I sort of understand why I was having trouble trying to set up my RAID. I am disappointed as I believe you can do a RAID setup on a PC with only two HDD's.

Rebo0ot

OSX has software raid built-in, so you could set up a RAID 0 array using Disk Utility. The major drawback is that you cannot boot off of your RAID array, meaning you must have a minimum of three disks (boot disk, 2xRAID disks).

So, since the G5 only has two disk connectors, you would indeed need an additional PCI Storage Controller. A basic controller card (either ATA or SATA) would let you use OSX software RAID. For maximum performance, you could get a card with a built in hardware RAID controller. That would let you boot from the array, but they will cost you at least $300 just for the card.

I'm not sure you can build a RAID array with individual external drives. There are aftermarket RAID enclosures that house more than one drive and connect through IEEE1394 ports (both 400 & 800). They are quite expensive and you would get better performance connceted directly to a PCI slot.

 

[warrenbert]

Do you think TIGER's release at the end of April will allow you to boot off of a RAID array?

No. It's a hardware thing. PC motherboards with built-in RAID controllers allow you to boot from the array. They control the functions that allow the operating system to see the striped disks as a (virtual) single disk. The PC's hardware RAID controller starts on boot first, then the operating system loads from the array.

Powermacs don't have a built-in hardware RAID controller. OSX has to completely load first and then the operating system uses software-RAID to mount your RAID disks.

You could save your money by not buying Tiger and then putting your money towards a RAID controller card. Then you could boot from a RAID array. The card's RAID controller would initialize on boot and then the operating system could load from your array.

Here is an interesting article on RAID 0 benchmarking and what the cost to benefit ratio is for the average user:

http://anandtech.com/storage/showdoc.aspx?i=2101

Here are some RAID cards I found:

http://www.newegg.com/app/ViewProductDesc.asp?description=16-123-111&depa=0
http://www.newegg.com/app/ViewProductDesc.asp?description=16-115-023&depa=0
http://www.newegg.com/app/ViewProductDesc.asp?description=16-115-020&depa=0

 

[Texasmeat]

....

Not true. I installed and booted off of a striped raid. I am typing this on my raid 0 setup right now. I wasnt sure if I could do it so I tried. Install was simple. Booted from CD and it recognized that I had 2 of the same hd/ asked if I wanted to stripe raid configure/I said yes/Installed the OS and everything has been working smoothly.I attached a picture of the system profiler showing the raid setup hdd's.

View attachment Picture 1.pdf

 

[warrenbert]

I can't believe the CompUSA guy was correct...even my local Apple Store reps seem pretty clueless beyond web-surfing and iTunes.

Thanks for taking the time to check things out. Did you read that article on the advantages and disadvantages of RAID 0 and RAID 1?

 

[Texasmeat]

....

Yeah I read the article. I disagree. It matters what you really expect to achieve with a raid. If you're thinking it's a bar-none huge performance gain, dont do it. If you want faster disk speeds and 40pts higher in xbench, get the raid 0 setup. In real world, yeah it's much faster than a single hard drive. Gameplay is smoother and access times are sick fast. I got my hard drive for $55 shipped from ebay and it was brand new in sealed factory package. When playing jedi academy (for instance) loading levels is almost instant. There's maybe a 2 second bleep before the next cinematic loads and the level starts. It's weird getting used to this because I was always used to waiting at least 30 seconds on my pc and even my g4's.

 

[hoverboard]

I'm doing the same

I just put a second drive of the same size into my Dual 2 and booted from the CD. The Installer didn't ask if I wanted to create a RAID, neither did Disk Utility when I opened it.

Now, Disk Utility did allow me to create a RAID, which I think I did properly (dragged the two drives into the RAID window, which was set to striped) and pressed 'create' Voila, I get the little RAID icon for a drive that's the size of my two 250's combined.

But when I exit the Utility and go into the Installer, it refuses to install OS X onto my RAID. Can you describe in more detail the process you went through and what I may have missed. Thanks a million....

Not true. I installed and booted off of a striped raid. I am typing this on my raid 0 setup right now. I wasnt sure if I could do it so I tried. Install was simple. Booted from CD and it recognized that I had 2 of the same hd/ asked if I wanted to stripe raid configure/I said yes/Installed the OS and everything has been working smoothly.I attached a picture of the system profiler showing the raid setup hdd's.

 

[Texasmeat]

...

You prety much got it from the sounds of it. You may need to format the drives in order to sucessfully install the os. Make sure that you setup the raid using striping (it'll say so in the field in disk util).Let me know how it turns out.