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How can I image an iBook G4 drive?

kuro68k

Experienced Member
Joined
Jul 1, 2019
Messages
109
I have an iBook G4 (identified as a PowerBook6,7 with 1GB of RAM) with Japanese OS. I want to make a backup of it before replacing it with an English OS. I'm struggling to reliably do it.

I downloaded an old Ubuntu 6 ISO and booted it. First problem is that the battery is dead, so the clock resets to 1980, and on booting most of the apps crash. I tried to image the drive with the following command:

Code:
sudo dd if=/dev/hda conv=sync,noerror bs=128k | split -b 2000m - /media/usbdrive/image.dd.

I was able to make backup images to a FAT32 formatted USB stick, but there is always filesystem corruption. I tried two different sticks and an SSD, all failed with the same issue. I have one complete image but I don't know if it's good or corrupt.

In an attempt to determine if it was good, I used md5sum with dd. The value from
Code:
dd if=/dev/hda conv=sync,noerror bs=128k | md5sum
was different to all the images I made, corrupt or otherwise.

I tried Lubuntu 16.04, but it won't boot on my iBook. It gets to the desktop and hangs. Is Ubuntu Server 16.04 worth trying?

Is there some free Mac software that can do this? Basically I just need to create a drive image that I can restore later if needs be. I don't want to take the drive out because it's a real pain on these iBooks.
 
Have you tried using ddrescue instead of dd?
Also I might be confusing the functionality of Apple's Disk Copy and OS X's Disk Utility but can't you save an image file of the hard disk using the pulldown menu and livebooting an install CD?
 
I have not tried ddrescue. I don't think that the drive is damaged in any way, but I'll give it a go.

I didn't know about the live install CD. I downloaded a couple from archive.org to try so I'll give those a go. Thanks.
 
What system does it run? MacOS can image itself, either using DiskCopy or with the hard disk utility in OS X. There's no need to boot some other OS and use 3rd-party software.
 
It is OS X 10.4.11. It's Japanese but I can read enough to operate it. I didn't know it could image itself, I will try that now...
 
I tried it and it said the drive was busy. I'll try again with the install disc.
 
I finally managed to burn an install disk. I think my stock of old DVD-R DLs is mostly damaged now, due to age. Eventually found one that worked.

The Disk Utility on the install disk does not allow you to save images to a FAT32 drive. It seems only have read capability. It can format a FAT32 drive, but not write files to it. In the end I formatted the disk a HFS, so once the imaging process is complete I will have to boot into Mac OS and copy it to a FAT32 drive.

One thing that isn't clear from the imaging process is if it actually verifies the image. I'll make two identical images and compare the files on Windows.
 
One thing that isn't clear from the imaging process is if it actually verifies the image. I'll make two identical images and compare the files on Windows.
No, it does not. It will add a hash to the image file itself so it can check the image when mounting. But it won't care about the integrity of the file system. (and when doing an image, that's how it should be, as any repair attempt could cause more damage)
 
No, it does not. It will add a hash to the image file itself so it can check the image when mounting. But it won't care about the integrity of the file system. (and when doing an image, that's how it should be, as any repair attempt could cause more damage)

What I mean is, does it re-read the drive to confirm that the image does in fact match the original data?

The problem I had with Ubuntu was that it would write the data to the external drive, but when I tried to read the data back the filesystem of the external drive was corrupt. The result being that part of the image data was lost, and I would not have been able to restore it. Ubuntu didn't even notice the corruption. Same with the install discs, drive wrote them without errors in most cases, but they failed verification.
 
I compared the two images, they both have different MD5 checksums. That probably means that the HDD is failing. It is rather old. Might have to open it up and replace it with something solid state, but I really don't want to because it's a bit of a nightmare on these iBooks. The battery needs rebuilding too, it doesn't even keep the time and date.

Edit: did anyone know if the time the image was created is stored in the file? That would explain it being different. I'll try a binary diff tomorrow.
 
Last edited:
I did the binary diff with WinMerge, using uncompressed .dmg files. There are many sections where there are differences. It looks like occasional small errors in places, and then some whole blocks that are corrupt.

The Apple Diagnostic tool says that the drive and everything else is okay, but it doesn't seem to be.

The only thing I can think of is to keep making uncompressed images, and write a script that compares several images and looks for instances of two or more agreeing and assuming that data is good. Ideally I'd parse the filesystem to look for errors, but that's a big undertaking. Another option would be to use Linux again and re-read sectors until I get a couple of successive reads that are the same, but I will need to investigate how to do that. Or maybe just give up, as it doesn't look like there is much on this machine at all, and I'll have to replace the drive anyway.

Not looking forward to opening this thing up...
 
Is there some free Mac software that can do this? Basically I just need to create a drive image that I can restore later if needs be. I don't want to take the drive out because it's a real pain on these iBooks.
Sorry if I missed something obvious, but to create a restorable image, is there any reason not to use Carbon Copy Cloner or SuperDuper? I think both are free for simple imaging, and I used SuperDuper for years with no issues.
 
Or you know, a mac of that era if you boot from a CD/DVD and just drag/drop from one drive to another it will just work.
 
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