Quadra 950 — Maximum bootable partition offset

[robin-fo]

My Quadra 950 refuses to boot a partition which lies at an offset of several tens of Gigabytes. Before it are some A/UX partitions. The first partition is bootable.

Is there a limitation of the offset of bootable volumes? Can this be mended with some special disk driver? I tried Apple and HDT with no difference, FWB makes it crash…

 

[Unknown_K]

What OS are you using other than A/UX?

System 7 allows 2GB partitions to be bootable, 7.5.2 to 8.x allow 4GB bootable partitions and I think 8.1 allows 2TB partitions but not bootable on 68K.

 

[robin-fo]

The partition in question is 1GB sized and Mac OS 8.1 is installed on it

 

[volvo242gt]

I'd be tempted to put the 8.1 partition first, then have your A/UX partitions afterward. My old Q660av would not boot a partition larger than 2GB, no matter what OS. But, once booted, it could read and write to Mac OS Extended (HFS+) formatted media, since 8.1 was installed.

 

[Realitystorm]

I've never seen anything documented about an offset limit...what I gave noticed is issues with too many partitions (more than 12). When you say, "before that there are some A/UX partitions", how many do you mean? There may also be a limit we don't know about, we a blowing well past the available storage sizes of the period

 

[MrFahrenheit]

From the research that I did a few years ago, the hard disk driver AND the system folder must exist in the first 2GB of a drive. I'm unsure if that's truly 2048MB (or 2,097,152 KB) or what.... Generally I create a 1.9GB partition as the first, and use that for the system folder.

Power Macs I think have the ability to boot Mac OS beyond the "first 2GB" rule, but I can't recall for sure. I do know that 68K Macs have this limitation.

 

[volvo242gt]

Yup, PowerMacs are fully HFS+ compatible and can boot partitions larger than 2GB.