[gberz3]

Hi All,

I'm having a problem with a system. The specs are as follows:


Dual 533 G4
1.5 GB Mem
250GB HD (using IDE Controller Card)


It seems that after I use around 150GB on the drive, if I delete large quantities of data (e.g. large video files, etc) the system on that partition chokes. The computer will sporadically boot into OpenFirmware and other times it will just hang at the boot apple. My only options on boot are 1) Boot into "single user mode" or 2) Boot to a separate 20GB partition on the same HD.

If anyone has any idea as to why exactly this is being cause, and how I can recover from it, it would be most appreciated. I've run 'fsck' and DiskWarrior on it about a million times, to no avail.

I don't fundamentally mind wiping the partition and restarting; as I've already done this about 4 times in the last 6 mths, but the fact that I'm not sure what's going on severely frustrates me. When I run 'fsck' I'm told that I need to check for an "ALTERNATE SUPERBLOCK" and that I've got a "BAD MAGIC NUMBER". I've googled these things to no end, but 99.9% of the forums end up suggesting DiskWarrior, which brings me back here.

Please advise. . .

Regards.

[reader50]

Check the website of whoever manufactured your IDE card. Look for a firmware update. It sounds like the card has a glitch in it's firmware.

Google is good, but for Apple Support reference information ... try Apple Support. Use the "Search Support" box near top-right of the page. If it doesn't return anything useful, click the "Advanced Search" link that comes up with the results. In the Advanced page, be sure to check the box to include archive results. Apple has a way of skipping serious technical info, but they often let useful tips slip in the past.

Going that route turned up these pages:
OSX Server 1.x - when to run fsck
OSX Server 1.x - when to force fsck to run

A Superblock gives critical info for a disk, including the format and pointers to various critical locations - like the root directory and volume bitmap. The first superblock is normally at block 8, and fsck will look for it there. If it's damaged, then fsck can't tell what format the disk uses, which makes any repair effort dangerous. The superblock is mirrored elsewhere on the disk because it's so important; the first mirror is normally at block 16.

The first article link gives this info, as well as how to search the disks for additional superblock mirrors if the first two are trashed. In practice, the superblock isn't likely to be written to after a disk is formatted, so damage to it means a serious failure in the OS, drivers, card firmware, or drive firmware. Of those, the IDE card's firmware is the most likely culprit. If there's no later firmware, contact the card manufacturer's support team. See if they've seen this before. Check their support FAQ first of course.

Apple Support isn't turning up any useful references to a magic number, but it has to be a checksum on some critical part of the disk. Like the superblock, indicating that it's damaged.

Diskwarrior is the best utility for fixing disk damage. But this type of damage shouldn't be happening, so using DW is only treating symptoms. Better to track down the real cause, and fix it. Then run a DW pass across the partition to leave everything clean.

[gberz3]

Simple firmware update allows me to now boot to the drive. Good call. Apparently that was a little too obvious for me.

Thanks reader50!