sparc disklabel

[luigi6699]

This is what comes of pride!

Frustrated with Solaris 10, I decided to take my sparc machine to gentoo instead. I booted off the minimal cd just fine, and launched into the familiar installation routine.

But wait! What's this about a "sun disklabel"? You mean I shouldn't have deleted that "whole disk" partition? Oh crap.

So I had to recreate my sun disklabel. I looked up my disk (20gb Seagate Barracuda ATA IV, model st320011a), and found the following values, which - AFAIK - are standard for disks over 8.8gb or so:

Logical cylinders 16,383
Logical heads 16
Logical sectors/track 63
Bytes per sector 512
Rotation speed 7200

So I use fdisk's "s" command, and specify a custom label - all entries default except as noted:
Heads 16
sectors/track 63
cylinders [default 38790 ??] 16383
alternate cylinders 2 (what are alternate cylinders?)
physical cylinders 16385 (ok, now I'm lost)
rotation speed [default 5400] 7200
Interleave factor 1
Extra sectors per cylinder 0 (you can have extra?)

This seems OK, until I try and partition the disk, and find myself with less than 10GB of space! I tried allowing the default number of cylinders, but that left me with even LESS space. What's going on??
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You never REALLY learn to swear until you own a computer.

[luigi6699]

What's awful is that when I calculate the size manually, I agree with the computer, rather than with the specs!

16383 X 16 X 63 X 512 = 8.4gb!

So what gives? Is this an LBA issue? What's going on here?
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You never REALLY learn to swear until you own a computer.

[luigi6699]

OK, so here is what I learned -
With disks larger than 8.4GB, Logical Block Addressing is used to address all that space. What that means is that the Cylinders X Heads X Tracks equation is officially obsolete. Any system from the last 10 years will ignore these calculations entirely, and just number the blocks itself, sequentially,

So the options in Fdisk's "s" command were irrelevant! As long as they multiplied up to 20Gb, the system didn't care.

*sigh*
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You never REALLY learn to swear until you own a computer.

[mark_alec]

Moved from Installing Gentoo to Gentoo on Sparc.
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www.gentoo.org.au || #gentoo-au

[sblaineyuk]

When I got my Sparc it had no disk partitions... I messed around with trying to find the right parameters, but what I ended up doing was downloading the first Solaris disk and going through the installer and either using the actual installer or Sun fdisk (I forget which ) to put the whole disk partition back on - with it automicatically detecting the right parameters. Then Bob was my uncle.