imac unexpectantly shuts down

Hi newbie here, with the following problem.

My imac unexpectedly shuts down after around 1 hour.
I've tried a fresh install of Lion 10.8.2 but still no joy.
Any suggestions would be gratefully received.
Thanks in advance.

Interval Since Last Panic Report: 10 sec
Panics Since Last Report: 1
Anonymous UUID: C4300164-39C1-06D2-E4D7-6FFD90632153

Sat Nov 3 21:10:35 2012
panic(cpu 1 caller 0xffffff800e2f7e6b): "hfs_vnop_link: error 2 updating vp @ 0xffffff80186ffaa8\n"@/SourceCache/xnu/xnu-2050.18.24/bsd/hfs/hfs_link.c:643
Backtrace (CPU 1), Frame : Return Address
0xffffff8085deba00 : 0xffffff800e01d626
0xffffff8085deba70 : 0xffffff800e2f7e6b
0xffffff8085debb80 : 0xffffff800e112346
0xffffff8085debbe0 : 0xffffff800e0fce98
0xffffff8085debf50 : 0xffffff800e3e182a
0xffffff8085debfb0 : 0xffffff800e0ced33

BSD process name corresponding to current thread: backupd

Mac OS version:
12C60

Kernel version:
Darwin Kernel Version 12.2.0: Sat Aug 25 00:48:52 PDT 2012; root:xnu-2050.18.24~1/RELEASE_X86_64
Kernel UUID: 69A5853F-375A-3EF4-9247-478FD0247333
Kernel slide: 0x000000000de00000
Kernel text base: 0xffffff800e000000
System model name: iMac9,1 (Mac-F2218EA9)

System uptime in nanoseconds: 3196938792171
last loaded kext at 1075441930743: com.apple.filesystems.afpfs 10.0 (addr 0xffffff7f900f3000, size 348160)
last unloaded kext at 336467422784: com.apple.filesystems.msdosfs 1.8 (addr 0xffffff7f900ad000, size 57344)
loaded kexts:
com.apple.filesystems.afpfs 10.0
com.apple.nke.asp_tcp 7.0.0
com.apple.driver.AppleHWSensor 1.9.5d0
com.apple.driver.AudioAUUC 1.60
com.apple.filesystems.autofs 3.0
com.apple.filesystems.ntfs 3.10
com.apple.iokit.IOUserEthernet 1.0.0d1
com.apple.iokit.IOBluetoothSerialManager 4.0.9f33
com.apple.Dont_Steal_Mac_OS_X 7.0.0
com.apple.driver.AGPM 100.12.69
com.apple.driver.AppleMikeyHIDDriver 122
com.apple.driver.AppleUpstreamUserClient 3.5.10
com.apple.iokit.CSRBluetoothHCIControllerUSBTransport 4.0.9f33
com.apple.driver.AppleHDA 2.3.1f2
com.apple.driver.AppleMikeyDriver 2.3.1f2
com.apple.driver.AppleBacklight 170.2.3
com.apple.GeForce 8.0.0
com.apple.driver.AppleUSBOpticalMouse 5.2.5
com.apple.nvenet 2.0.19
com.apple.driver.ApplePolicyControl 3.2.11
com.apple.driver.AirPort.Brcm4331 602.15.22
com.apple.driver.ACPI_SMC_PlatformPlugin 1.0.0
com.apple.driver.AppleLPC 1.6.0
com.apple.driver.AppleMCCSControl 1.0.33
com.apple.AppleFSCompression.AppleFSCompressionTypeDataless 1.0.0d1
com.apple.AppleFSCompression.AppleFSCompressionTypeZlib 1.0.0d1
com.apple.BootCache 34
com.apple.iokit.SCSITaskUserClient 3.5.1
com.apple.driver.XsanFilter 404
com.apple.iokit.IOAHCIBlockStorage 2.2.2
com.apple.driver.AppleRTC 1.5
com.apple.driver.AppleUSBHub 5.2.5
com.apple.driver.AppleFWOHCI 4.9.6
com.apple.driver.AppleAHCIPort 2.4.1
com.apple.driver.AppleUSBEHCI 5.4.0
com.apple.driver.AppleUSBOHCI 5.2.5
com.apple.driver.AppleEFINVRAM 1.6.1
com.apple.driver.AppleHPET 1.7
com.apple.driver.AppleACPIButtons 1.6
com.apple.driver.AppleSMBIOS 1.9
com.apple.driver.AppleACPIEC 1.6
com.apple.driver.AppleAPIC 1.6
com.apple.driver.AppleIntelCPUPowerManagementClient 196.0.0
com.apple.nke.applicationfirewall 4.0.39
com.apple.security.quarantine 2
com.apple.driver.AppleIntelCPUPowerManagement 196.0.0
com.apple.security.SecureRemotePassword 1.0
com.apple.driver.AppleBluetoothHIDMouse 175.8
com.apple.driver.AppleHIDMouse 175.8
com.apple.driver.IOBluetoothHIDDriver 4.0.9f33
com.apple.kext.triggers 1.0
com.apple.iokit.IOSurface 86.0.3
com.apple.iokit.IOSerialFamily 10.0.6
com.apple.iokit.IOBluetoothFamily 4.0.9f33
com.apple.driver.DspFuncLib 2.3.1f2
com.apple.iokit.IOAudioFamily 1.8.9fc10
com.apple.kext.OSvKernDSPLib 1.6
com.apple.driver.AppleBacklightExpert 1.0.4
com.apple.iokit.IOFireWireIP 2.2.5
com.apple.iokit.AppleBluetoothHCIControllerUSBTransport 4.0.9f33
com.apple.driver.AppleHDAController 2.3.1f2
com.apple.iokit.IOHDAFamily 2.3.1f2
com.apple.driver.AppleGraphicsControl 3.2.11
com.apple.iokit.IO80211Family 500.15
com.apple.iokit.IONetworkingFamily 3.0
com.apple.driver.NVSMU 2.2.9
com.apple.driver.AppleSMC 3.1.4d2
com.apple.driver.IOPlatformPluginLegacy 1.0.0
com.apple.driver.AppleSMBusPCI 1.0.10d0
com.apple.driver.IOPlatformPluginFamily 5.2.0d16
com.apple.driver.AppleSMBusController 1.0.10d0
com.apple.nvidia.nv50hal 8.0.0
com.apple.NVDAResman 8.0.0
com.apple.iokit.IONDRVSupport 2.3.5
com.apple.iokit.IOGraphicsFamily 2.3.5
com.apple.iokit.IOUSBHIDDriver 5.2.5
com.apple.driver.AppleUSBMergeNub 5.2.5
com.apple.driver.AppleUSBComposite 5.2.5
com.apple.iokit.IOSCSIMultimediaCommandsDevice 3.5.1
com.apple.iokit.IOBDStorageFamily 1.7
com.apple.iokit.IODVDStorageFamily 1.7.1
com.apple.iokit.IOCDStorageFamily 1.7.1
com.apple.iokit.IOAHCISerialATAPI 2.5.0
com.apple.iokit.IOSCSIArchitectureModelFamily 3.5.1
com.apple.iokit.IOUSBUserClient 5.2.5
com.apple.iokit.IOFireWireFamily 4.5.5
com.apple.iokit.IOAHCIFamily 2.2.1
com.apple.iokit.IOUSBFamily 5.4.0
com.apple.driver.AppleEFIRuntime 1.6.1
com.apple.iokit.IOHIDFamily 1.8.0
com.apple.iokit.IOSMBusFamily 1.1
com.apple.security.sandbox 220
com.apple.kext.AppleMatch 1.0.0d1
com.apple.security.TMSafetyNet 7
com.apple.driver.DiskImages 344
com.apple.iokit.IOStorageFamily 1.8
com.apple.driver.AppleKeyStore 28.21
com.apple.driver.AppleACPIPlatform 1.6
com.apple.iokit.IOPCIFamily 2.7.2
com.apple.iokit.IOACPIFamily 1.4
com.apple.kec.corecrypto 1.0
Model: iMac9,1, BootROM IM91.008D.B08, 2 processors, Intel Core 2 Duo, 2 GHz, 4 GB, SMC 1.44f0
Graphics: NVIDIA GeForce 9400, NVIDIA GeForce 9400, PCI, 256 MB
Memory Module: BANK 0/DIMM0, 2 GB, DDR3, 1067 MHz, 0x80CE, 0x4D34373142353737334448302D4348392020
Memory Module: BANK 1/DIMM0, 2 GB, DDR3, 1067 MHz, 0x838A, 0x5052494E4345544F4E000000000000000000
AirPort: spairport_wireless_card_type_airport_extreme (0x14E4, 0x8E), Broadcom BCM43xx 1.0 (5.106.98.81.22)
Bluetooth: Version 4.0.9f33 10885, 2 service, 18 devices, 1 incoming serial ports
Network Service: Built-in Ethernet, Ethernet, en0
Serial ATA Device: WDC WD1600AAJS-40H3A0, 160.04 GB
Serial ATA Device: HL-DT-ST DVDRW GA11N
USB Device: Built-in iSight, apple_vendor_id, 0x8502, 0x24400000 / 2
USB Device: Bluetooth USB Host Controller, 0x0a12 (Cambridge Silicon Radio Ltd.), 0x0001, 0x04300000 / 3
USB Device: Hub in Apple Extended USB Keyboard, apple_vendor_id, 0x1003, 0x04100000 / 2
USB Device: Apple Optical USB Mouse, apple_vendor_id, 0x0307, 0x04120000 / 5
USB Device: Apple Extended USB Keyboard, apple_vendor_id, 0x020c, 0x04130000 / 4

What you're experiencing is a kernel panic. KPs are generally caused by faulty hardware but can also be generated by rogue software. Try booting your iMac into safe mode and operate there for awhile to see if the KP occurs again. Press your shift key as soon as you hear the POST sound (bong!) to allow the machine to boot to safe mode. While in safe mode, many drivers and functions will be restricted including sound.

If it operates normally while in safe mode, try booting to your recovery partition by pressing command + r when you hear the sound. From the recovery partition enter Disk Utility and do a verify - repair for the hard drive. Let us know the results.

Thanks, i'll give it a try and report back. I was suspecting a hardware problem but is it possible to run AHT without the original discs?

For that model you will need the original discs to access Apple Hardware Test. Models that shipped with Lion and later can access through the net to Apple's web site. Do as chscag suggests and verify and repair the hard drive.

Hi, thanks again for your help. Much appreciated.

So the imac is running at the mo in safe mode at present, with no KPs.

Last night, I put the imac into recovery mode, verified the partition disc and all was OK.
Also took the opportunity to verify & repair permissions. Then tried running as normal (just Firefox operating) but unfortunately another KP within an hour of use.

Report listed below, any suggestion will be gratefully received since its just numbers and letters to me:

Interval Since Last Panic Report: 11675 sec
Panics Since Last Report: 2
Anonymous UUID: C4300164-39C1-06D2-E4D7-6FFD90632153

Sun Nov 4 09:34:22 2012
panic(cpu 1 caller 0xffffff80080f7e6b): "hfs_vnop_link: error 2 updating vp @ 0xffffff8019e88c98\n"@/SourceCache/xnu/xnu-2050.18.24/bsd/hfs/hfs_link.c:643
Backtrace (CPU 1), Frame : Return Address
0xffffff807a773a00 : 0xffffff8007e1d626
0xffffff807a773a70 : 0xffffff80080f7e6b
0xffffff807a773b80 : 0xffffff8007f12346
0xffffff807a773be0 : 0xffffff8007efce98
0xffffff807a773f50 : 0xffffff80081e182a
0xffffff807a773fb0 : 0xffffff8007eced33

BSD process name corresponding to current thread: backupd

Mac OS version:
12C60

Kernel version:
Darwin Kernel Version 12.2.0: Sat Aug 25 00:48:52 PDT 2012; root:xnu-2050.18.24~1/RELEASE_X86_64
Kernel UUID: 69A5853F-375A-3EF4-9247-478FD0247333
Kernel slide: 0x0000000007c00000
Kernel text base: 0xffffff8007e00000
System model name: iMac9,1 (Mac-F2218EA9)

System uptime in nanoseconds: 4179279021158
last loaded kext at 2478827259844: com.apple.filesystems.afpfs 10.0 (addr 0xffffff7f8a02b000, size 348160)
last unloaded kext at 110479910761: com.apple.driver.AppleFileSystemDriver 3.0.1 (addr 0xffffff7f89d4b000, size 8192)
loaded kexts:
com.apple.filesystems.afpfs 10.0
com.apple.nke.asp_tcp 7.0.0
com.apple.driver.AppleHWSensor 1.9.5d0
com.apple.filesystems.ntfs 3.10
com.apple.driver.AudioAUUC 1.60
com.apple.iokit.IOBluetoothSerialManager 4.0.9f33
com.apple.driver.AppleMikeyHIDDriver 122
com.apple.iokit.IOUserEthernet 1.0.0d1
com.apple.Dont_Steal_Mac_OS_X 7.0.0
com.apple.driver.AppleHDA 2.3.1f2
com.apple.driver.AppleMikeyDriver 2.3.1f2
com.apple.driver.AGPM 100.12.69
com.apple.driver.AppleUSBOpticalMouse 5.2.5
com.apple.iokit.CSRBluetoothHCIControllerUSBTransport 4.0.9f33
com.apple.driver.ApplePolicyControl 3.2.11
com.apple.driver.ACPI_SMC_PlatformPlugin 1.0.0
com.apple.driver.AppleBacklight 170.2.3
com.apple.driver.AppleLPC 1.6.0
com.apple.filesystems.autofs 3.0
com.apple.driver.AppleUpstreamUserClient 3.5.10
com.apple.driver.AppleMCCSControl 1.0.33
com.apple.GeForce 8.0.0
com.apple.AppleFSCompression.AppleFSCompressionTypeDataless 1.0.0d1
com.apple.AppleFSCompression.AppleFSCompressionTypeZlib 1.0.0d1
com.apple.BootCache 34
com.apple.iokit.SCSITaskUserClient 3.5.1
com.apple.driver.XsanFilter 404
com.apple.iokit.IOAHCIBlockStorage 2.2.2
com.apple.driver.AirPort.Brcm4331 602.15.22
com.apple.nvenet 2.0.19
com.apple.driver.AppleUSBOHCI 5.2.5
com.apple.driver.AppleUSBHub 5.2.5
com.apple.driver.AppleFWOHCI 4.9.6
com.apple.driver.AppleAHCIPort 2.4.1
com.apple.driver.AppleUSBEHCI 5.4.0
com.apple.driver.AppleRTC 1.5
com.apple.driver.AppleEFINVRAM 1.6.1
com.apple.driver.AppleHPET 1.7
com.apple.driver.AppleACPIButtons 1.6
com.apple.driver.AppleSMBIOS 1.9
com.apple.driver.AppleACPIEC 1.6
com.apple.driver.AppleAPIC 1.6
com.apple.driver.AppleIntelCPUPowerManagementClient 196.0.0
com.apple.nke.applicationfirewall 4.0.39
com.apple.security.quarantine 2
com.apple.driver.AppleIntelCPUPowerManagement 196.0.0
com.apple.security.SecureRemotePassword 1.0
com.apple.driver.AppleBluetoothHIDMouse 175.8
com.apple.driver.AppleHIDMouse 175.8
com.apple.driver.IOBluetoothHIDDriver 4.0.9f33
com.apple.iokit.IOSerialFamily 10.0.6
com.apple.iokit.IOSurface 86.0.3
com.apple.iokit.IOBluetoothFamily 4.0.9f33
com.apple.driver.DspFuncLib 2.3.1f2
com.apple.iokit.IOAudioFamily 1.8.9fc10
com.apple.kext.OSvKernDSPLib 1.6
com.apple.iokit.IOFireWireIP 2.2.5
com.apple.iokit.AppleBluetoothHCIControllerUSBTransport 4.0.9f33
com.apple.driver.AppleHDAController 2.3.1f2
com.apple.iokit.IOHDAFamily 2.3.1f2
com.apple.driver.AppleSMBusPCI 1.0.10d0
com.apple.driver.AppleGraphicsControl 3.2.11
com.apple.driver.AppleSMC 3.1.4d2
com.apple.driver.IOPlatformPluginLegacy 1.0.0
com.apple.driver.AppleBacklightExpert 1.0.4
com.apple.driver.IOPlatformPluginFamily 5.2.0d16
com.apple.kext.triggers 1.0
com.apple.driver.AppleSMBusController 1.0.10d0
com.apple.nvidia.nv50hal 8.0.0
com.apple.NVDAResman 8.0.0
com.apple.iokit.IONDRVSupport 2.3.5
com.apple.iokit.IOGraphicsFamily 2.3.5
com.apple.iokit.IOUSBHIDDriver 5.2.5
com.apple.driver.AppleUSBMergeNub 5.2.5
com.apple.driver.AppleUSBComposite 5.2.5
com.apple.iokit.IOSCSIMultimediaCommandsDevice 3.5.1
com.apple.iokit.IOBDStorageFamily 1.7
com.apple.iokit.IODVDStorageFamily 1.7.1
com.apple.iokit.IOCDStorageFamily 1.7.1
com.apple.iokit.IOAHCISerialATAPI 2.5.0
com.apple.iokit.IOSCSIArchitectureModelFamily 3.5.1
com.apple.iokit.IO80211Family 500.15
com.apple.iokit.IONetworkingFamily 3.0
com.apple.iokit.IOUSBUserClient 5.2.5
com.apple.iokit.IOFireWireFamily 4.5.5
com.apple.iokit.IOAHCIFamily 2.2.1
com.apple.iokit.IOUSBFamily 5.4.0
com.apple.driver.NVSMU 2.2.9
com.apple.driver.AppleEFIRuntime 1.6.1
com.apple.iokit.IOHIDFamily 1.8.0
com.apple.iokit.IOSMBusFamily 1.1
com.apple.security.sandbox 220
com.apple.kext.AppleMatch 1.0.0d1
com.apple.security.TMSafetyNet 7
com.apple.driver.DiskImages 344
com.apple.iokit.IOStorageFamily 1.8
com.apple.driver.AppleKeyStore 28.21
com.apple.driver.AppleACPIPlatform 1.6
com.apple.iokit.IOPCIFamily 2.7.2
com.apple.iokit.IOACPIFamily 1.4
com.apple.kec.corecrypto 1.0
Model: iMac9,1, BootROM IM91.008D.B08, 2 processors, Intel Core 2 Duo, 2 GHz, 4 GB, SMC 1.44f0
Graphics: NVIDIA GeForce 9400, NVIDIA GeForce 9400, PCI, 256 MB
Memory Module: BANK 0/DIMM0, 2 GB, DDR3, 1067 MHz, 0x80CE, 0x4D34373142353737334448302D4348392020
Memory Module: BANK 1/DIMM0, 2 GB, DDR3, 1067 MHz, 0x838A, 0x5052494E4345544F4E000000000000000000
AirPort: spairport_wireless_card_type_airport_extreme (0x14E4, 0x8E), Broadcom BCM43xx 1.0 (5.106.98.81.22)
Bluetooth: Version 4.0.9f33 10885, 2 service, 18 devices, 0 incoming serial ports
Network Service: Built-in Ethernet, Ethernet, en0
Serial ATA Device: WDC WD1600AAJS-40H3A0, 160.04 GB
Serial ATA Device: HL-DT-ST DVDRW GA11N
USB Device: Built-in iSight, apple_vendor_id, 0x8502, 0x24400000 / 2
USB Device: Bluetooth USB Host Controller, 0x0a12 (Cambridge Silicon Radio Ltd.), 0x0001, 0x04300000 / 3
USB Device: Hub in Apple Extended USB Keyboard, apple_vendor_id, 0x1003, 0x04100000 / 2
USB Device: Apple Optical USB Mouse, apple_vendor_id, 0x0307, 0x04120000 / 5
USB Device: Apple Extended USB Keyboard, apple_vendor_id, 0x020c, 0x04130000 / 4

Are you running Time Machine? I noticed both kernel panic reports indicate that "backupd" caused the panic. If you're running TM, make sure your external hard drive is accessible and not crashing.

Try this: Turn off Time Machine and remove your external hard drive. Operate that way for a length of time. Let's see if the kernel panics stop. Let us know.

If you are booting with external attached this can cause precisely what you are experiencing. Also try an SMC reset with externals not connected and see if there is any improvement:-

iMac won't boot with external drives attached - MacRumors Forums

Hi all, thanks for your suggestions.

Looks like indeed the KPs are related to a corrupt TM back up. I cant fix it using disk utility since its a NAS WD My Book Live with no USB or firewire for direct connection.

It's a 'bedroom' iMac' so i'm not particularly worried about the loss of data so I'll simply try and create a new back up and delete the old corrupted data.

Thanks again for all your help.