View Full Version : RAID volume too large?

05-28-2001, 10:37 PM
I just finished building my weirdo, vertically mounted, four-drive Burly RAID enclosure, and I just got an error message I never thought I'd see. After I initialized all four drives on my PTPro and created one big 16GB volume between them, I unplugged it and hooked it up to my 6100 Power Mac (the one that will be mated to my Quadra 950, but right now it's still separate). It booted up and then, when it got to the desktop, gave me this error message:

"The SoftRAID Driver has detected a volume which is too large to be accessed by the File System on this machine."

Huh? The 6100 is running OS 8.6 and the RAID volume is formatted HFS+. I thought that would prevent any problems with too-large volumes. What gives?

05-29-2001, 01:11 PM
Follow-up: I deleted the 16GB volume and then tried to use SoftRAID to set up a new one. It wouldn't let me go higher than 4MB. I guess the 6100 is somehow limited in its ROM as to how large a volume it can access? Like the SE/30 couldn't access volumes larger than 2GB? Can anyone confirm?

It took me a little while to realize that just because I can't access the 16GB volume with my 6100 doesn't mean all my work for the RAID was for nought. I can just set up four 4GB volumes and they'll still be striped across all four drives. Duh! *smack forehead*

BTW, I got the temperatures down to between 30 and 40 degrees C, when testing the center of the non-PCB side. The frontmost drive is the coolest at 30C, presumably because it gets the full benefit of the vents in the front panel, then the 2nd drive back is hottest at 40C, with the third and fourth drives a little lower each. I did this by putting two small fans from a front-bezel cooler inside the bottom of the front bezel, to blow air into the very bottom of the case; then from there the air is blown up from below by two 60mm case fans; the air flows up between all the drives to the top, where there is also a flat twin-fan Ultrathin cooler mounted upside down to help pull the air up; and from there it's sucked out the back by the main case fan. Haven't drilled any extra exhaust holes in the case yet, we'll see if I need to after I actually start putting these drives to use.

The inside of the case is absolute spaghetti. Each drive has two wires for the HD light, six for the ID selector switch, one for the temp probe, plus SCSI and power. And there are four power splitters in there for all the fans. I also have the HVD converter board mounted sideways in the back of the case, and the HVD terminator at the end of the cable secured by velcro on top of the power supply. The good thing is, since the drives are all mounted vertically with the connector side facing up, I can open the case and do maintenance without removing drives. Or switch out one drive without removing any others.

05-29-2001, 01:14 PM
Current versions of SoftRAID are not compatible with NuBus machines. In order to switch between a NuBus and PCI Mac you will need to run something like HDT or maybe HDST (I don't know about this one).

Also, in NuBus machines, contained in their ROM, is a maximum size of 2GB for a boot volume. Any non-boot volume can of course be much larger, but any boot volume should not exceed 2GB by even one bit or byte. I have seen reports of some being able to boot from larger volumes, but no accompanying long term reports of stability. k

05-29-2001, 01:17 PM
Oh, if I recall correctly, HDST limits you to two drives in RAID. k

05-29-2001, 01:24 PM
Well now that's strange. I've been gettin SoftRAID 2.2.2 to work on the 6100, although it does lock up every once in awhile. All I have to do then is just force quit and try again, maybe restart first. The only real error I've been having was the "volume-too-large" error.

BTW, for those wanting to know what kind of performance I'm getting out of these things: all four drives are really old 4GB Seagate Barracuda half-height thermo-monsters, model ST15150WD. The "D" in their model number is for Differential, as in High-Voltage Differential, which is why I need the HVD converter board inside the case. These drives, all Fast-and-Wide but of course adapted down to narrow and plugged into the external 5MB/sec bus, are getting me a whopping 2.5MB/sec sustained read AND write!

05-29-2001, 01:50 PM
NOTE: About NuBus based Macintosh computers:
SoftRAID requires a PCI based Mac OS system to perform its drive acceleration. This is because 68k and PowerPC based Macs with NuBus slots both require a 68K driver on the disk drive. SoftRAID's high performance acceleration only works with PCI based systems. If you have a PowerPC NuBus machine (6100, 7100, 8100, Power Base, etc., then SoftRAID's native driver will not work.
http://www.softraid.com/compfaqs.lasso k

05-29-2001, 03:44 PM

Not that I would be getting much acceleration over a 5MB/sec bus anyway. I was just RAIDing these things together for the sake of doing it. Maybe I could try SilverLining Pro anyway, since I can't use HDST (won't stripe more than two drives, although I could do two dual-drive RAIDS) and I'm not going to spend the money to upgrade FWB HDT when I take the 6100 to OS 9.1. I wonder if 9.1 will even work on the 6100...

OK, back to the drawing board. Let's see what I can turn up this time...