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Marko Karppinen · Feb 1, 2003, 08:35 AM

Xserve was the first Mac to allow booting off of drives mirrored with OS X's software RAID. Since Apple claims the MDD and FW800 PowerMacs use the "Xserve architecture", I was wondering if this feature is available on these systems as well.

Any ideas?

solitere · Feb 1, 2003, 03:46 PM

Originally posted by Marko Karppinen:
Xserve was the first Mac to allow booting off of drives mirrored with OS X's software RAID. Since Apple claims the MDD and FW800 PowerMacs use the "Xserve architecture", I was wondering if this feature is available on these systems as well.
Any ideas?

Mac OS X 10.2 Software RAID should work with SCSI and IDE hard disks. But you cannot use RAID set with your startup disk. Which means you atleast will need 2 additional HD to use it!

But Honestly i have not tryed it!

Eriamjh · Feb 1, 2003, 10:04 PM

You can boot OSX to a RAID startup disk (I have done it), but if you ever boot to OS9, you cannot get back to the RAID stripe unless you have another hard drive with OSX on it, you boot to that, then reboot to the RAID.

schalliol · Feb 2, 2003, 02:23 AM

Very interesting. I was told that no New World (>Beige G3 - holding option at startup gives you the machine) cannot boot off of a software RAID, and even SoftRAID's forthcoming ver. 3 does not support it, however they have indicated that mirrors created by it and OS X will boot.

I do know that you can boot off of an IDE Stripe with SIIG/ACard's ATA RAID product, as many have done it.

I am wondering what I should do in this regard (see this post: http://forums.macnn.com/showthread.p...postid=1198397

Eriamjh, could you please tell us more about your current/past RAID 0 config? Have you done any performance tests?

Marko Karppinen · Feb 2, 2003, 05:22 AM

I've digged deeper into this and it seems that 10.2 supports booting off of mirrored drives. That's obviously much easier to implement than booting off a striped array. So I guess I'm going to go and configure those 2x180GB drives into my new mac after alll...

schalliol · 05:59 AM

Eriamjh seems to have been able to do it striped as well. Hopefully more details will come there.

Ric · Feb 2, 2003, 06:53 AM

I've been booting 10.2 (now 10.2.3) off a striped array using Apple's RAID software on my G4 dual 533 since September last year with no problems.

2 x IBM 36 gig drives on an Adaptec 29160 single channel SCSI card. I've heard reports that a 39160 card setup doesn't work so perhaps it depends on the config.

schalliol · Feb 2, 2003, 06:55 AM

This is VERY interesting. I'll have to contact the guys at SoftRAID to see what they think.

When you did the install, you just created the array and installed the OS on it? And you selected it as startup and it went?

What's your config (machine)?

Ric · 07:21 AM

Originally posted by schalliol:

When you did the install, you just created the array and installed the OS on it? And you selected it as startup and it went?

What's your config (machine)? [/B]

That's exactly what I did - started from 10.2 CD, launched disk utility, created striped SCSI RAID, installed OS on it and came back in the room to find that the machine had rebooted itself off the RAID, right into the registration sequence. I was actually quite surprised as it wasn't supposed to work

This was just after 10.2.2 came out and I was going to upgrade to that before trying to boot. It turned out plain 10.2 could do it too.

The machine is a standard Apple G4 533 MP with 1G RAM. I also have an ATA drive (stock) for backup in case the RAID's flaky but so far it's been perfect.

[Edit: sp.]

Ric · Feb 2, 2003, 07:17 AM

BTW, SoftRAID have apparently said that they won't support booting on X. Maybe they will in a later rev, but I imagine they'll go for performance first, as Apple's RAID is not that speedy.

schalliol · Feb 2, 2003, 01:37 PM

I'm going to have to send them a message at SoftRAID. They say they do not support booting in new world machines because it can't be done. Given that it can, I'll be interested to hear their response.

On the OS X RAID performance issue, I'd like to note that even my nice Ultra2 array is slower than a single IDE, this should not be so.

nerd · Feb 5, 2003, 06:32 PM

Same boat here, running off 2 Seagate LVD drives attached to an Apple 2940U2B (Adaptec) card. No problems.

I did have X booting off a RAID in 10.1 but the trick was to use Carbon Copy Cloner because non of the 10.1 installers would let you install on a RAID. That all changed with 10.2.

Brad

schalliol · Feb 5, 2003, 07:01 PM

So, you're stuck with booting off of IDE, eh? How's your performance? I assume you're using Apple's RAID software. Personally, I hope it's the software, but I'm actually getting slower performance on the Ultra2 array than my single ATA. Sigh... SoftRAID should be here w/in the month or so, we'll see if it improves things.

Mark James at SoftRAID confirmed that it will not boot a RAID 0.