Archive for November, 2007

OpenAerialMap Prorotype

Posted in Locality and Space, OpenAerialMap on November 26th, 2007 at 11:38:40

Prototype of a worldwide seamless multi-resolution baselayer powered by open data:


DiskWarrior: Fix for “journal magic is bad”

Posted in DiskWarrior, OS X on November 3rd, 2007 at 11:41:30

Jess’s Powerbook died last night. Trying to start it up, I found that it was unable to mount the drive read/write. The symptom of this that we were able to see, by the way, was that the computer just ‘hung’ at the Apple with the spinning logo under it, because some file was unable to be written to and therefore startup hung waiting for it to come back.

I figured out how to get into single-user mode (apple-S during startup) and ran an fsck on the disk. (Before this, the disk could be mounted read-only, but not read-write.) It seemed to work, for the most part, though it complained of a bad journal, so I couldn’t mount the drive read/write. Figuring I’d start over after the fsck and see if that let it boot any farther, I restarted… and found that my fsck had let the HFS volume figure out that the Journal really *was* bad, and that it was no longer going to even mount read only. (Sigh.) The error message was “journal magic is bad”, followed by “nfs_boot_init failed with 6”. I was royally pissed at myself for failing to buy the Firewire cable and get data off of it first, but figured I’d fix it in the morning.

I went out and bought a Firewire cable this morning and mounted the disk to my laptop. It showed up in Disk Utility, and I ran “Repair Disk” on it. Disk Utility reported that it had repaired the disk successfully, and even claimed it could mount the disk successfully, but never did. Trying to boot the computer still paniced immediately, with the same “journal magic is bad” message. So, following the advice of Some Guy On the Internet, I went ahead and bought DiskWarrior, and he’s 100% right: “Dont waste any more time. Get Disk Warrior. Run it on the volume. It just works. Done.”

Of course, for some people, it’s not so simple: disable_journal.c was written by an Apple user who couldn’t get even DiskWarrior to fix the problem, so instead wrote a small C app to hack the bits of the drive. (Ouch!) But for me, DiskWarrior was just the best $100 I’ve ever spent. (Though I do wish I could have skipped the $9 shipping, since I just bought it online and I don’t really need or want a copy in the mail.)

Thanks to DiskWarrior, Jess now has her laptop back, with nary a file misplaced. You can’t ask for anything better than that — and all told, it only took about 15 minutes, including the run to the store to buy the Firewire cable.