My wife’s Mac mini (G4, 1.42 GHz) has been crashing several times per day lately, and I’m almost out of options. I think I’ve found an issue with Lacie Firewire drives and PPC Mac minis, but I’ll let you be the judge of that.

The system in question is running OS X 10.4.8 with 1 GB of RAM. It boots off a Lacie mini Hard Drive & Hub. It’s been crashing with a kernel panic that looks about like this:

Mon Jan  8 22:06:24 2007
panic(cpu 0 caller 0x000E3DDC): vnode_writedone: numoutput < 0
Latest stack backtrace for cpu 0:
  Backtrace:
     0x00095138 0x00095650 0x00026898 0x000E3DDC 0x000D8A24 0x2D8F2230 0x2D8E4FF4 0x2DFA4C80 
     0x2DFA7A38 0x2DFA7B38 0x2D7F1FFC 0x2D7F222C 0x2DA7727C 0x2DA776B8 0x2D9D2C6C 0x2D9D26EC 
     0x2D594A44 0x2D576040 0x2D575940 0x2D5E1AD4 0x2D5D1450 0x002D0B94 0x002CFA5C 0x000A9314 
  Kernel loadable modules in backtrace (with dependencies):
     com.apple.iokit.IOSCSIReducedBlockCommandsDevice(1.4.9)@0x2dfa3000
        dependency: com.apple.iokit.IOStorageFamily(1.5)@0x2d8df000
        dependency: com.apple.iokit.IOSCSIArchitectureModelFamily(1.4.9)@0x2d7ea000
     com.apple.iokit.IOFireWireSerialBusProtocolTransport(1.4.4)@0x2da75000
        dependency: com.apple.iokit.IOSCSIArchitectureModelFamily(1.4.9)@0x2d7ea000
        dependency: com.apple.iokit.IOFireWireSBP2(1.7.5)@0x2d9cf000
        dependency: com.apple.iokit.IOFireWireFamily(2.2.5)@0x2d56c000
     com.apple.iokit.IOFireWireSBP2(1.7.5)@0x2d9cf000
        dependency: com.apple.iokit.IOFireWireFamily(2.2.5)@0x2d56c000
     com.apple.iokit.IOStorageFamily(1.5)@0x2d8df000
     com.apple.iokit.IOSCSIArchitectureModelFamily(1.4.9)@0x2d7ea000
     com.apple.driver.AppleFWOHCI(2.5.3)@0x2d5cb000
        dependency: com.apple.iokit.IOPCIFamily(1.7)@0x275f7000
        dependency: com.apple.iokit.IOFireWireFamily(2.2.5)@0x2d56c000
     com.apple.iokit.IOFireWireFamily(2.2.5)@0x2d56c000
Proceeding back via exception chain:
   Exception state (sv=0x2762FA00)
      PC=0x00000000; MSR=0x0000D030; DAR=0x00000000; DSISR=0x00000000; LR=0x00000000; R1=0x00000000; XCP=0x00000000 (Unknown)

Kernel version:
Darwin Kernel Version 8.8.0: Fri Sep  8 17:18:57 PDT 2006; root:xnu-792.12.6.obj~1/RELEASE_PPC

The second line is the key; it’s crashing due to vnode_writedone: numoutput < 0. Searching for that error gives me 2 other people who have had the same problem, both within the last month. Both other cases involve PPC Mac minis and Lacie FW hard drives. This can’t be that new of a problem, because I’ve been suffering since August when I was running 10.4.7.

I’ve tried a number of fixes with no success. I’ve dusted out the mini, reseated the RAM, performed disk and permission repairs, re-installed the 10.4.8 combo updater, monkeyed with power saving settings, and removed all non-essential hardware, all without any success.

I just opened a ticket with Lacie. If anyone else is seeing similar problems, let me know and I’ll add it to the Lacie ticket.