How can I identify what my problem is from a Panic Report?

Question

My iMac (late 2009 ) keeps hanging and the screen freezes.

Anonymous UUID:       B0BCD2D8-C300-6D40-6A72-6C102AF8254A

Mon May 18 22:28:44 2015

*** Panic Report ***
panic(cpu 1 caller 0xffffff7f926bbbb4): NVRM[0/2:0:0]: Read Error 0x00000200: CFG 0x30000000 0x00000c42 0x0a7d1fa0, BAR0 0xd2000000 0xffffff80ac6dd000 0x096a80a1, D0, P0/4
Backtrace (CPU 1), Frame : Return Address
0xffffff8019b43980 : 0xffffff8011b2bda1 
0xffffff8019b43a00 : 0xffffff7f926bbbb4 
0xffffff8019b43ac0 : 0xffffff7f9278518e 
0xffffff8019b43b00 : 0xffffff7f929f7dbd 
0xffffff8019b43ba0 : 0xffffff7f92a3990f 
0xffffff8019b43be0 : 0xffffff7f92a131d3 
0xffffff8019b43c50 : 0xffffff7f92a102fb 
0xffffff8019b43ca0 : 0xffffff7f927c70c8 
0xffffff8019b43d00 : 0xffffff7f926bc3d5 
0xffffff8019b43d50 : 0xffffff7f9266f74c 
0xffffff8019b43da0 : 0xffffff7f9266e1d6 
0xffffff8019b43dc0 : 0xffffff7f940a9b8a 
0xffffff8019b43e90 : 0xffffff7f940a9a5c 
0xffffff8019b43ee0 : 0xffffff7f940a8692 
0xffffff8019b43f00 : 0xffffff8011b5e759 
0xffffff8019b43fb0 : 0xffffff8011c125b7 
      Kernel Extensions in backtrace:
         com.apple.nvidia.classic.NVDAResmanTesla(10.0)[796AE430-39FB-3255-8161-D52AFA28EE2B]@0xffffff7f9266b000->0xffffff7f928d4fff
            dependency: com.apple.iokit.IOPCIFamily(2.9)[52E715FC-521D-3869-B2EA-5228FA4BEA34]@0xffffff7f9233c000
            dependency: com.apple.iokit.IONDRVSupport(2.4.1)[C0B8A85D-B32A-3F24-B4FC-B62B3BBF9E57]@0xffffff7f9265b000
            dependency: com.apple.iokit.IOGraphicsFamily(2.4.1)[82EAD591-67E3-39CB-A232-A8095CA30E92]@0xffffff7f92614000
         com.apple.nvidia.classic.NVDANV50HalTesla(10.0)[7FE40648-F15F-3E18-91E2-FDDDF4CDA355]@0xffffff7f928df000->0xffffff7f92b88fff
            dependency: com.apple.nvidia.classic.NVDAResmanTesla(10.0.0)[796AE430-39FB-3255-8161-D52AFA28EE2B]@0xffffff7f9266b000
            dependency: com.apple.iokit.IOPCIFamily(2.9)[52E715FC-521D-3869-B2EA-5228FA4BEA34]@0xffffff7f9233c000
         com.apple.driver.AGPM(110.19.5)[79098073-4EDB-3F1D-BCB7-14C090A70098]@0xffffff7f940a6000->0xffffff7f940b9fff
            dependency: com.apple.iokit.IOPCIFamily(2.9)[52E715FC-521D-3869-B2EA-5228FA4BEA34]@0xffffff7f9233c000
            dependency: com.apple.driver.IOPlatformPluginFamily(5.9.1d7)[43F5FC1D-9651-3595-861F-56F299525FF5]@0xffffff7f9312f000
            dependency: com.apple.iokit.IONDRVSupport(2.4.1)[C0B8A85D-B32A-3F24-B4FC-B62B3BBF9E57]@0xffffff7f9265b000
            dependency: com.apple.iokit.IOGraphicsFamily(2.4.1)[82EAD591-67E3-39CB-A232-A8095CA30E92]@0xffffff7f92614000
            dependency: com.apple.AppleGraphicsDeviceControl(3.10.22)[44D7223C-9628-3FEA-A3B8-27DE9E1CE0C3]@0xffffff7f940a0000

BSD process name corresponding to current thread: kernel_task

Mac OS version:
14D136

Kernel version:
Darwin Kernel Version 14.3.0: Mon Mar 23 11:59:05 PDT 2015; root:xnu-2782.20.48~5/RELEASE_X86_64
Kernel UUID: 4B3A11F4-77AA-3D27-A22D-81A1BC5B504D
Kernel slide:     0x0000000011800000
Kernel text base: 0xffffff8011a00000
__HIB  text base: 0xffffff8011900000
System model name: iMac9,1 (Mac-F2218FC8)

System uptime in nanoseconds: 13482834065856
last loaded kext at 304929693034: com.apple.filesystems.msdosfs 1.10 (addr 0xffffff7f941c2000, size 69632)
last unloaded kext at 365753283403: com.apple.filesystems.msdosfs   1.10 (addr 0xffffff7f941c2000, size 61440)
loaded kexts:
com.sophos.kext.sav 9.2.50
com.sophos.nke.swi  9.2.50
com.apple.driver.AudioAUUC  1.70
com.apple.driver.AppleHWSensor  1.9.5d0
com.apple.driver.AGPM   110.19.5
com.apple.filesystems.autofs    3.0
com.apple.iokit.IOBluetoothSerialManager    4.3.4f4
com.apple.driver.AppleOSXWatchdog   1
com.apple.driver.AppleMikeyHIDDriver    124
com.apple.driver.AppleHDA   272.18
com.apple.driver.ACPI_SMC_PlatformPlugin    1.0.0
com.apple.iokit.BroadcomBluetoothHostControllerUSBTransport 4.3.4f4
com.apple.driver.AppleLPC   1.7.3
com.apple.iokit.IOUserEthernet  1.0.1
com.apple.Dont_Steal_Mac_OS_X   7.0.0
com.apple.driver.AppleHWAccess  1
com.apple.driver.AppleHV    1
com.apple.driver.AppleIntelSlowAdaptiveClocking 4.0.0
com.apple.GeForceTesla  10.0.0
com.apple.driver.AppleMikeyDriver   272.18
com.apple.driver.AppleUpstreamUserClient    3.6.1
com.apple.driver.AppleBacklight 170.7.4
com.apple.driver.AppleMCCSControl   1.2.11
com.apple.driver.AppleIRController  327.5
com.apple.AppleFSCompression.AppleFSCompressionTypeDataless 1.0.0d1
com.apple.AppleFSCompression.AppleFSCompressionTypeZlib 1.0.0d1
com.apple.BootCache 36
com.apple.iokit.SCSITaskUserClient  3.7.5
com.apple.driver.XsanFilter 404
com.apple.iokit.IOAHCIBlockStorage  2.7.1
com.apple.driver.AppleUSBHub    705.4.2
com.apple.driver.AppleFWOHCI    5.5.2
com.apple.driver.AppleUSBOHCI   656.4.1
com.apple.driver.AppleAHCIPort  3.1.2
com.apple.driver.AirPort.Brcm4331   800.20.24
com.apple.nvenet    2.0.22
com.apple.driver.AppleUSBEHCI   705.4.14
com.apple.driver.AppleRTC   2.0
com.apple.driver.AppleHPET  1.8
com.apple.driver.AppleACPIButtons   3.1
com.apple.driver.AppleSMBIOS    2.1
com.apple.driver.AppleACPIEC    3.1
com.apple.driver.AppleAPIC  1.7
com.apple.driver.AppleIntelCPUPowerManagementClient 218.0.0
com.apple.nke.applicationfirewall   161
com.apple.security.quarantine   3
com.apple.security.TMSafetyNet  8
com.apple.driver.AppleIntelCPUPowerManagement   218.0.0
com.apple.driver.AppleBluetoothHIDMouse 185.3
com.apple.driver.AppleHIDMouse  185.3
com.apple.driver.IOBluetoothHIDDriver   4.3.4f4
com.apple.AppleGraphicsDeviceControl    3.10.22
com.apple.kext.triggers 1.0
com.apple.iokit.IOSerialFamily  11
com.apple.driver.DspFuncLib 272.18
com.apple.kext.OSvKernDSPLib    1.15
com.apple.driver.IOPlatformPluginLegacy 1.0.0
com.apple.iokit.IOBluetoothHostControllerUSBTransport   4.3.4f4
com.apple.driver.IOPlatformPluginFamily 5.9.1d7
com.apple.iokit.IOSurface   97.4
com.apple.iokit.IOBluetoothFamily   4.3.4f4
com.apple.iokit.IOSlowAdaptiveClockingFamily    1.0.0
com.apple.driver.AppleHDAController 272.18
com.apple.iokit.IOHDAFamily 272.18
com.apple.iokit.IOAudioFamily   203.3
com.apple.vecLib.kext   1.2.0
com.apple.driver.AppleSMBusPCI  1.0.12d1
com.apple.nvidia.classic.NVDANV50HalTesla   10.0.0
com.apple.nvidia.classic.NVDAResmanTesla    10.0.0
com.apple.iokit.IOUSBUserClient 705.4.0
com.apple.iokit.IOFireWireIP    2.2.6
com.apple.driver.AppleBacklightExpert   1.1.0
com.apple.driver.AppleSMC   3.1.9
com.apple.driver.AppleSMBusController   1.0.13d1
com.apple.iokit.IONDRVSupport   2.4.1
com.apple.iokit.IOGraphicsFamily    2.4.1
com.apple.driver.AppleUSBHIDKeyboard    176.2
com.apple.driver.AppleHIDKeyboard   176.2
com.apple.iokit.IOUSBHIDDriver  705.4.0
com.apple.iokit.IOSCSIBlockCommandsDevice   3.7.5
com.apple.iokit.IOUSBMassStorageClass   3.7.2
com.apple.driver.AppleUSBMergeNub   705.4.0
com.apple.driver.AppleUSBComposite  705.4.9
com.apple.iokit.IOSCSIMultimediaCommandsDevice  3.7.5
com.apple.iokit.IOBDStorageFamily   1.7
com.apple.iokit.IODVDStorageFamily  1.7.1
com.apple.iokit.IOCDStorageFamily   1.7.1
com.apple.iokit.IOAHCISerialATAPI   2.6.1
com.apple.iokit.IOSCSIArchitectureModelFamily   3.7.5
com.apple.iokit.IOFireWireFamily    4.5.6
com.apple.iokit.IOAHCIFamily    2.7.5
com.apple.iokit.IO80211Family   730.60
com.apple.iokit.IONetworkingFamily  3.2
com.apple.iokit.IOUSBFamily 720.4.4
com.apple.driver.NVSMU  2.2.9
com.apple.driver.AppleEFINVRAM  2.0
com.apple.driver.AppleEFIRuntime    2.0
com.apple.iokit.IOHIDFamily 2.0.0
com.apple.iokit.IOSMBusFamily   1.1
com.apple.security.sandbox  300.0
com.apple.kext.AppleMatch   1.0.0d1
com.apple.driver.AppleKeyStore  2
com.apple.driver.AppleMobileFileIntegrity   1.0.5
com.apple.driver.AppleCredentialManager 1.0
com.apple.driver.DiskImages 396
com.apple.iokit.IOStorageFamily 2.0
com.apple.iokit.IOReportFamily  31
com.apple.driver.AppleFDEKeyStore   28.30
com.apple.driver.AppleACPIPlatform  3.1
com.apple.iokit.IOPCIFamily 2.9
com.apple.iokit.IOACPIFamily    1.4
com.apple.kec.corecrypto    1.0
com.apple.kec.Libm  1
com.apple.kec.pthread   1
Model: iMac9,1, BootROM IM91.008D.B08, 2 processors, Intel Core 2 Duo, 2.93 GHz, 4 GB, SMC 1.37f3
Graphics: NVIDIA GeForce GT 120, NVIDIA GeForce GT 120, PCIe, 256 MB
Memory Module: BANK 0/DIMM0, 2 GB, DDR3, 1067 MHz, 0x80CE, 0x4D34373142353637334448312D4346382020
Memory Module: BANK 1/DIMM0, 2 GB, DDR3, 1067 MHz, 0x80CE, 0x4D34373142353637334448312D4346382020
AirPort: spairport_wireless_card_type_airport_extreme (0x14E4, 0x8E), Broadcom BCM43xx 1.0 (5.106.98.100.24)
Bluetooth: Version 4.3.4f4 15601, 3 services, 27 devices, 1 incoming serial ports
Network Service: AirPort, AirPort, en1
Serial ATA Device: WDC WD6400AAKS-40H2B0, 640.14 GB
Serial ATA Device: OPTIARC DVD RW AD-5670S
USB Device: Built-in iSight
USB Device: Samsung STORY Station
USB Device: Keyboard Hub
USB Device: Apple Keyboard
USB Device: IR Receiver
USB Device: BRCM2046 Hub
USB Device: Bluetooth USB Host Controller
Thunderbolt Bus: 

Answer 1

Based on your crash log, the line with:

Kernel Extensions in backtrace: com.apple.nvidia.classic.NVDAResmanTesla

... and those following it immediately point to a potential issue with your GPU driver or the GPU itself.

Restart in hardware test mode by booting while holding D. You may need the DVD that came with the computer to do this. Run the fast, non-extended test, and if there are any GPU problems that it can detect, it will tell you so. Otherwise, while there still may be hardware problems, the last thing to do before giving up is to do a quick reinstall of the OS. You won't lose your data, but it will refresh all of the system files, and may fix the issue if the problem is a corrupted driver.

Answer 2

The answer to your question depends on some data you didn't provide, so here is your "choose your own adventure" for Kernel Panics on OS X.

If this is a one time event, forget about it: How serious are occasional kernel panics?

If this is repeatable, you can actually dig into the items from multiple dumps that are common to them all. If you can't do this analysis, ask us to explain with some details.

If this is not repeatable but not occasional, you'll have to troubleshoot a bit to narrow down the cause: How can I troubleshoot Kernel Panics on my iMac

If all else fails, you can pay Apple (or a knowledgable person) to analyze your specific dump. Service and consultants are at https://locate.apple.com

Answer 3

Here is what I read:

You have inserted a USB device with some .msdofs file system.

That lead to GPU panic.

Nothing wrong with the GPU, it just could not handle the .msdosfs.

While at it please Disable the Sophos virus scanner just in case it was responsible for that.

Run the non invasive system report app called EtreCheck to get additional information on your system.

Check the content of that USB.