[John Strung]

According to TIL N25249 just posted, older iMacs upgraded with larger hard drives may not boot unless the drive is partitioned with a boot partition smaller than 8 Gigs.

I have a Rev A. iMac, and I can boot fine into a 10GB HD, with NO paritions.

Damn Double Post! I have also used the same HD in a 333 iMac. The TIL might only apply to certain HD, or maybe really big ones


[This message has been edited by James Z (edited 02-24-2001).]

[Cipher13]

The 8 gig (myth) is for pre-NWR machines I believe.

Cipher13

[John Strung]

Forgive my ignorance, but what is NWR?

[Kon-El]

Its always been gospel in this forum that the rev. A & rev. B iMacs only read the first 8 gb of the hard drive, so that with larger drives it had to be partitioned.

With a 10 gb hard drive perhaps your system folder is in the first 8 gb?

I'm getting a 20.4 gb drive iunstalled, so if this isn;t true, I'd liek to know vis something that backs this up, as if I don;t need partitions, I don't want them at all.

------------------
Pax Christi,
-Nik!
http://iMac.RulesTheWeb.com

[CaseCom]

I assume Cipher means "New World ROM."

I have read that Macs search a maximum of 8 GB when looking for the Mac OS ROM file. So, when booting from a partition larger than 8 GB, the System Folder needs to be in the first 8 GB. (Note that the TIL says MAY not boot from a larger partition.)

The "myth," I think, is when people say that a bootable partition needs to be within the first 8 gigs of a drive. People have booted from a partition at he very tail end of a 30 gig drive.

My question about this TIL article is, why only Rev A-D iMacs? Obviously many new iMacs are shipping with unpartitioned drives larger than 8 gigs. Is this not a problem with slot-loading iMacs? Newer bootROM or something?

[This message has been edited by CaseCom (edited 02-24-2001).]

[John Strung]

I am puzzled by the TIL as well as there have been discussions on the MacFixit board which would lead me to believe that the problem is not limited to iMacs.

See for instance see this thread which seems to indicate the problem can occur in a dual processor G4.


The TIL I mentioned in my earlier post seems to be the first acknowledgement in any TIL of the 8 gig problem though.

[John Strung]

Kon-El, there are lots of other good reasons to partition. See:

Partitioning Pros and Cons

[MarkusYamamoto]

I just upgraded to a IBM 75 GB 7200rpm drive with 3 partitions and it works fine.
The drive is partitioned to 10 GB /10 GB / 53 GB the first is for Mac OS 9.1 and the
second will be OS X when it comes out and the last for just files and backup. I have
always partitioned my drives in three parts previously for a System / Programs / Files
configuration because it makes it a lot easier and faster to run TechTool Pro if I just
want to run it on the System part or whatever also, it makes it easier to do a complete
reinstall of an OS on just the System partition without screwing with the other parts.
You can also put a different OS on each partition and boot from them seperately.
Be careful about where you install and leave files,applications and aliases put them in
the right place or you will be confused where thing are installed.

Markus

[TimmyDee51]

I can tell you that for rev. A-D iMacs the 8 GB partition limit is no myth. I had two OS 9.x system folders on my new 30 GB drive, one on the first 8 GB and one on the next 8 GB. The one on the first 8 GB was the only one I could boot from. I had to reformat so both system folders could sit on the first 8 GB and now I do not have any problem.

[Kon-El]

In that thread that John directed me to, people talk about puting their IE, iCab & Nutscrape caches on a RAM disk. Has anyone here done that to great results?

------------------
Pax Christi,
-Nik!
http://iMac.RulesTheWeb.com

[gacuna]

I have a 20 gig HD, it works perfect.

------------------
ga.

[John]

Folks,

I have experienced this issue. Let me explain.

I have a Rev/A iMac, with a G4 upgrade card and a 45GB Drive. Upon receiving the drive, I installed Mac OS 9.04 and then proceeded to transfer all the old info of my older 6GB drive that shipped with the machine.

Everything wortked fine for a while, until I tried to do a clean install of Mac OS 9.1 (after a few months of adding data and moving data around on the 45GB drive.

When I did a clean install of 9.1, I restarted the iMac, thinking that there should be no problems... was I wrong.

The first few times I rebooted the machine, it would get far enough in the boot process to load the Mac OS 9.1 start up screen, but would proceed no further (left it on all night one night, to see it in the morning, stuck in the exact same boot sequence that I'd left it in)

I furiously started seaching the web on another machine here in the office. I search Apple's TIL's first and found no info, then turned to MacFixit, and found a few references to something akin to my problems.

The problems that others were seeing were the same as mine, and were only happening on large drives. It seemed that I might have found my problem, with no easy solution.

The issue is that there are a few files that *must* reside within the first 8 physical GB of the start up drive. I'm not exactly sure which files, but they seem to be the Mac OS ROM, the System, and the Finder.

If those files don't reside in the first 8 physical GB of the drive, then the machine won't boot. bottom line.

I couldn't get the machine to boot, no matter how many times I moved the ROM and System around on the drive after booting up off of a utility disk, nor could I get the old Mac OS installation to boot.... so I was left the the option of reformatting the disk.

While I was deciding to reformat, I planned accordingly, so that I could always have a few different partitions that resided in the first 8GB of the drive:

2.GB
2 GB
2 GB
2 GB

8 GB
8 GB
10 GB

is now my partitioning scheme. This is so that I can have Mac OS 9.1 installed, Mac OS X installed (sometime in the future) LinuxPPC and TurboLinux installed on this single machine, incase I ever want them, and have no problems with booting.

I've learned to live with this set up, and am getting used to it, but be warned....

the 8 GB issue is not a myth. It's true, and it hurts if it happens to you.

Hope the info helps all.

I think partitioning is absolutely neccessary! For example, at work I have a Sawtooth G4 with a 10 and 8 GB drive. I have partitioned the 10 into Part.1 (my workhorse system - 9.0.4) Part.2 (Swap volume for Virt. memory as well as Photoshop swapping) Part.3 (Basically a dup of Part.1 kind of as backup) Part. 4 (specially setup 9.0.4 for use with Norton Util's) Part.5 (Mac OSX PB) Part.6 (Some data I create, or for experimenting - I work off a wonderful Sun-based server on a gigabit network), 8 GB drive has Part.1 (os 9.1) and Part.2 (data Backup or just plain extra space for other junk and experiments). Anyway I can simply boot from what ever I want (although being a Sawtooth I can't choose at startup). When I have problems I boot from another partition and use Norton to fix the "busted" one (which goes even faster because the volume is smaller as a partition than as a whole). I don't fragment my "workhorse" drive by constantly writing and erasing to and from it (!) as well as never writing to my swap partition so it is never fragmented and the system as well as Photoshop always have huge hanging-together blocks for scratching (I honestly will do Photoshop collages up to 1 gigabyte with ease !) I can boot to a partition which I could care less about (so to speak) and experiment with ResEdit, or do initial system updates or what not.

At home I have an iMac DV which I partitioned 8 times (the limit with Apple's own software) and dumped SuSe Linux 7.0, Mac OSX, OS 9.0.4, etc on it (also swap volumes, and data volumes). At home I can choose during boot-up with the boot manager (AGP Mac's) which System/volume should start-up. I can only say, partitioning is the only way to go. Actually I got all these ideas from UNIX people! OSX apparently makes its own images for swapping and what not so that those who choose to leave a disc as one partition can. I wonder if that is all good, and if I will be competent enough under OSX to continue to work as I have (maybe I won't need to be so cautious under OSX!)

I think I posted my ramblings in the wrong place. I wanted them to be posted under the partitioning area. Sorry.

[Cipher13]

Originally posted by CaseCom:
I assume Cipher means "New World ROM."

Yep, thats it, sorry.
Pre New World Rom, and pre UMA (Universal Motherboard Architecture)... basically, pre-USB and- pretty colours.
The "soft Macs".

Cipher13