Name | Theory_2773-2990768-367_0 |
Workunit | 229873288 |
Created | 21 Jan 2025, 1:01:25 UTC |
Sent | 21 Jan 2025, 6:39:53 UTC |
Report deadline | 1 Feb 2025, 6:39:53 UTC |
Received | 21 Jan 2025, 7:48:50 UTC |
Server state | Over |
Outcome | Computation error |
Client state | Compute error |
Exit status | -1073741819 (0xC0000005) STATUS_ACCESS_VIOLATION |
Computer ID | 10681416 |
Run time | 9 sec |
CPU time | |
Validate state | Invalid |
Credit | 0.00 |
Device peak FLOPS | 3.13 GFLOPS |
Application version | Theory Simulation v300.60 (vbox64_theory) windows_x86_64 |
Peak working set size | 10.86 MB |
Peak swap size | 6.39 MB |
Peak disk usage | 0.87 MB |
<core_client_version>8.0.2</core_client_version> <![CDATA[ <message> (unknown error) (317) - exit code 3221225477 (0xc0000005)</message> <stderr_txt> 2025-01-21 01:47:56 (14028): vboxwrapper version 26208 2025-01-21 01:47:56 (14028): BOINC client version: 8.0.2 2025-01-21 01:47:57 (14028): Detected: VirtualBox VboxManage Interface (Version: 5.2.8) 2025-01-21 01:47:58 (14028): Detected: Heartbeat check (file: 'heartbeat' every 1200.000000 seconds) 2025-01-21 01:47:58 (14028): Successfully copied 'init_data.xml' to the shared directory. 2025-01-21 01:47:58 (14028): Successfully copied 'input' to the shared directory. 2025-01-21 01:47:58 (14028): Create VM. (boinc_6fc358c34099f3b7, slot#0) 2025-01-21 01:47:58 (14028): Setting Memory Size for VM. (630MB) 2025-01-21 01:47:59 (14028): Setting CPU Count for VM. (1) 2025-01-21 01:47:59 (14028): Setting Chipset Options for VM. 2025-01-21 01:47:59 (14028): Setting Graphics Controller Options for VM. 2025-01-21 01:48:00 (14028): Setting Boot Options for VM. 2025-01-21 01:48:00 (14028): Setting Network Configuration for NAT. 2025-01-21 01:48:00 (14028): Enabling VM Network Access. 2025-01-21 01:48:00 (14028): Disabling USB Support for VM. 2025-01-21 01:48:01 (14028): Disabling COM Port Support for VM. 2025-01-21 01:48:01 (14028): Disabling LPT Port Support for VM. 2025-01-21 01:48:01 (14028): Disabling Audio Support for VM. 2025-01-21 01:48:02 (14028): Disabling Clipboard Support for VM. 2025-01-21 01:48:02 (14028): Disabling Drag and Drop Support for VM. 2025-01-21 01:48:02 (14028): Adding storage controller(s) to VM. 2025-01-21 01:48:02 (14028): Adding virtual disk drive to VM. (Theory_2025_01_16_prod.vdi) 2025-01-21 01:48:04 (14028): Adding VirtualBox Guest Additions to VM. 2025-01-21 01:48:04 (14028): Adding network bandwidth throttle group to VM. (Defaulting to 1024GB) 2025-01-21 01:48:04 (14028): forwarding host port 61521 to guest port 80 2025-01-21 01:48:05 (14028): Enabling remote desktop for VM. 2025-01-21 01:48:05 (14028): Required extension pack not installed, remote desktop not enabled. 2025-01-21 01:48:05 (14028): Enabling shared directory for VM. 2025-01-21 01:48:06 (14028): Starting VM using VBoxManage interface. (boinc_6fc358c34099f3b7, slot#0) 2025-01-21 01:48:08 (14028): Error in start VM for VM: -1073741819 Command: VBoxManage -q startvm "boinc_6fc358c34099f3b7" --type headless Output: Waiting for VM "boinc_6fc358c34099f3b7" to power on... VBoxManage.exe: error: The virtual machine 'boinc_6fc358c34099f3b7' has terminated unexpectedly during startup with exit code -1073741819 (0xc0000005) VBoxManage.exe: error: Details: code E_FAIL (0x80004005), component MachineWrap, interface IMachine 2025-01-21 01:48:08 (14028): VM failed to start. 2025-01-21 01:48:08 (14028): Could not start 2025-01-21 01:48:08 (14028): ERROR: VM failed to start 2025-01-21 01:48:08 (14028): Powering off VM. 2025-01-21 01:48:08 (14028): Deregistering VM. (boinc_6fc358c34099f3b7, slot#0) 2025-01-21 01:48:08 (14028): Removing network bandwidth throttle group from VM. 2025-01-21 01:48:08 (14028): Removing VM from VirtualBox. Hypervisor System Log: 00:00:00.501421 HostDnsMonitorProxy::notify 00:00:00.621200 VD: VDInit finished with VINF_SUCCESS 00:00:00.621200 VirtualBox: object created 00:00:01.023574 ERROR [COM]: aRC=VBOX_E_OBJECT_NOT_FOUND (0x80bb0001) aIID={9570b9d5-f1a1-448a-10c5-e12f5285adad} aComponent={VirtualBoxWrap} aText={Could not find a registered machine named 'boinc_6fc358c34099f3b7'}, preserve=false aResultDetail=0 00:00:01.294276 Saving settings file "C:\ProgramData\BOINC\slots\0\boinc_6fc358c34099f3b7\boinc_6fc358c34099f3b7.vbox" with version "1.16-windows" 00:00:01.341163 Saving settings file "C:\Users\jeff\.VirtualBox\VirtualBox.xml" with version "1.12-windows" 00:00:01.565120 Saving settings file "C:\ProgramData\BOINC\slots\0\boinc_6fc358c34099f3b7\boinc_6fc358c34099f3b7.vbox" with version "1.16-windows" 00:00:01.898461 Saving settings file "C:\ProgramData\BOINC\slots\0\boinc_6fc358c34099f3b7\boinc_6fc358c34099f3b7.vbox" with version "1.16-windows" 00:00:02.153587 Saving settings file "C:\ProgramData\BOINC\slots\0\boinc_6fc358c34099f3b7\boinc_6fc358c34099f3b7.vbox" with version "1.16-windows" 00:00:02.440080 Saving settings file "C:\ProgramData\BOINC\slots\0\boinc_6fc358c34099f3b7\boinc_6fc358c34099f3b7.vbox" with version "1.16-windows" 00:00:02.721319 Saving settings file "C:\ProgramData\BOINC\slots\0\boinc_6fc358c34099f3b7\boinc_6fc358c34099f3b7.vbox" with version "1.16-windows" 00:00:03.018192 Saving settings file "C:\ProgramData\BOINC\slots\0\boinc_6fc358c34099f3b7\boinc_6fc358c34099f3b7.vbox" with version "1.16-windows" 00:00:03.283848 Saving settings file "C:\ProgramData\BOINC\slots\0\boinc_6fc358c34099f3b7\boinc_6fc358c34099f3b7.vbox" with version "1.16-windows" 00:00:03.627599 Saving settings file "C:\ProgramData\BOINC\slots\0\boinc_6fc358c34099f3b7\boinc_6fc358c34099f3b7.vbox" with version "1.16-windows" 00:00:03.846648 Saving settings file "C:\ProgramData\BOINC\slots\0\boinc_6fc358c34099f3b7\boinc_6fc358c34099f3b7.vbox" with version "1.16-windows" 00:00:04.127885 Saving settings file "C:\ProgramData\BOINC\slots\0\boinc_6fc358c34099f3b7\boinc_6fc358c34099f3b7.vbox" with version "1.16-windows" 00:00:04.409099 Saving settings file "C:\ProgramData\BOINC\slots\0\boinc_6fc358c34099f3b7\boinc_6fc358c34099f3b7.vbox" with version "1.16-windows" 00:00:04.690405 Saving settings file "C:\ProgramData\BOINC\slots\0\boinc_6fc358c34099f3b7\boinc_6fc358c34099f3b7.vbox" with version "1.16-windows" 00:00:04.971649 Saving settings file "C:\ProgramData\BOINC\slots\0\boinc_6fc358c34099f3b7\boinc_6fc358c34099f3b7.vbox" with version "1.16-windows" 00:00:05.252837 Saving settings file "C:\ProgramData\BOINC\slots\0\boinc_6fc358c34099f3b7\boinc_6fc358c34099f3b7.vbox" with version "1.16-windows" 00:00:05.534125 Saving settings file "C:\ProgramData\BOINC\slots\0\boinc_6fc358c34099f3b7\boinc_6fc358c34099f3b7.vbox" with version "1.16-windows" 00:00:06.081234 ERROR [COM]: aRC=VBOX_E_OBJECT_NOT_FOUND (0x80bb0001) aIID={85cd948e-a71f-4289-281e-0ca7ad48cd89} aComponent={SessionMachine} aText={No storage device attached to device slot 0 on port 0 of controller 'Hard Disk Controller'}, preserve=false aResultDetail=0 00:00:06.081234 ERROR [COM]: aRC=VBOX_E_OBJECT_NOT_FOUND (0x80bb0001) aIID={85cd948e-a71f-4289-281e-0ca7ad48cd89} aComponent={SessionMachine} aText={No storage device attached to device slot 0 on port 0 of controller 'Hard Disk Controller'}, preserve=false aResultDetail=0 00:00:06.081234 Saving settings file "C:\ProgramData\BOINC\slots\0\boinc_6fc358c34099f3b7\boinc_6fc358c34099f3b7.vbox" with version "1.16-windows" 00:00:06.362513 Saving settings file "C:\ProgramData\BOINC\slots\0\boinc_6fc358c34099f3b7\boinc_6fc358c34099f3b7.vbox" with version "1.16-windows" 00:00:06.674951 ERROR [COM]: aRC=VBOX_E_OBJECT_NOT_FOUND (0x80bb0001) aIID={85cd948e-a71f-4289-281e-0ca7ad48cd89} aComponent={SessionMachine} aText={No storage device attached to device slot 0 on port 0 of controller 'Hard Disk Controller'}, preserve=false aResultDetail=0 00:00:06.674951 Saving settings file "C:\ProgramData\BOINC\slots\0\boinc_6fc358c34099f3b7\boinc_6fc358c34099f3b7.vbox" with version "1.16-windows" 00:00:06.721832 ERROR [COM]: aRC=VBOX_E_OBJECT_NOT_FOUND (0x80bb0001) aIID={85cd948e-a71f-4289-281e-0ca7ad48cd89} aComponent={SessionMachine} aText={No storage device attached to device slot 0 on port 0 of controller 'Hard Disk Controller'}, preserve=false aResultDetail=0 00:00:06.721832 Saving settings file "C:\ProgramData\BOINC\slots\0\boinc_6fc358c34099f3b7\boinc_6fc358c34099f3b7.vbox" with version "1.16-windows" 00:00:06.862500 Saving settings file "C:\ProgramData\BOINC\slots\0\boinc_6fc358c34099f3b7\boinc_6fc358c34099f3b7.vbox" with version "1.16-windows" 00:00:07.221874 ERROR [COM]: aRC=VBOX_E_OBJECT_NOT_FOUND (0x80bb0001) aIID={85cd948e-a71f-4289-281e-0ca7ad48cd89} aComponent={SessionMachine} aText={No storage device attached to device slot 0 on port 1 of controller 'Hard Disk Controller'}, preserve=false aResultDetail=0 00:00:07.221874 ERROR [COM]: aRC=VBOX_E_OBJECT_NOT_FOUND (0x80bb0001) aIID={85cd948e-a71f-4289-281e-0ca7ad48cd89} aComponent={SessionMachine} aText={No storage device attached to device slot 0 on port 1 of controller 'Hard Disk Controller'}, preserve=false aResultDetail=0 00:00:07.221874 Saving settings file "C:\ProgramData\BOINC\slots\0\boinc_6fc358c34099f3b7\boinc_6fc358c34099f3b7.vbox" with version "1.16-windows" 00:00:07.503060 Saving settings file "C:\ProgramData\BOINC\slots\0\boinc_6fc358c34099f3b7\boinc_6fc358c34099f3b7.vbox" with version "1.16-windows" 00:00:07.784500 Saving settings file "C:\ProgramData\BOINC\slots\0\boinc_6fc358c34099f3b7\boinc_6fc358c34099f3b7.vbox" with version "1.16-windows" 00:00:08.597033 Saving settings file "C:\ProgramData\BOINC\slots\0\boinc_6fc358c34099f3b7\boinc_6fc358c34099f3b7.vbox" with version "1.16-windows" 00:00:09.143905 ERROR [COM]: aRC=VBOX_E_OBJECT_NOT_FOUND (0x80bb0001) aIID={85cd948e-a71f-4289-281e-0ca7ad48cd89} aComponent={SessionMachine} aText={No storage device attached to device slot 0 on port 2 of controller 'Hard Disk Controller'}, preserve=false aResultDetail=0 00:00:09.143905 ERROR [COM]: aRC=VBOX_E_OBJECT_NOT_FOUND (0x80bb0001) aIID={85cd948e-a71f-4289-281e-0ca7ad48cd89} aComponent={SessionMachine} aText={No storage device attached to device slot 0 on port 2 of controller 'Hard Disk Controller'}, preserve=false aResultDetail=0 00:00:09.143905 ERROR [COM]: aRC=E_FAIL (0x80004005) aIID={85cd948e-a71f-4289-281e-0ca7ad48cd89} aComponent={SessionMachine} aText={This machine does not have any snapshots}, preserve=false aResultDetail=0 00:00:11.378443 Watcher ERROR [COM]: aRC=E_FAIL (0x80004005) aIID={85cd948e-a71f-4289-281e-0ca7ad48cd89} aComponent={MachineWrap} aText={The virtual machine 'boinc_6fc358c34099f3b7' has terminated unexpectedly during startup with exit code -1073741819 (0xc0000005)}, preserve=false aResultDetail=0 00:00:11.378443 Watcher Reaper: Pid 10380 (288c) exited normally: -1073741819 (0xc0000005) 00:00:11.487863 ERROR [COM]: aRC=E_FAIL (0x80004005) aIID={85cd948e-a71f-4289-281e-0ca7ad48cd89} aComponent={SessionMachine} aText={This machine does not have any snapshots}, preserve=false aResultDetail=0 00:00:11.581657 Saving settings file "C:\ProgramData\BOINC\slots\0\boinc_6fc358c34099f3b7\boinc_6fc358c34099f3b7.vbox" with version "1.16-windows" 00:00:11.878902 Saving settings file "C:\Users\jeff\.VirtualBox\VirtualBox.xml" with version "1.12-windows" 00:00:16.969198 main VirtualBox: object deletion starts 00:00:16.969198 Watcher ERROR [COM]: aRC=E_ACCESSDENIED (0x80070005) aIID={9570b9d5-f1a1-448a-10c5-e12f5285adad} aComponent={VirtualBoxWrap} aText={The object is not ready}, preserve=false aResultDetail=0 00:00:16.969198 main VirtualBox: object deleted VM Execution Log: VM Startup Log: VM Trace Log: S Port: 1 Maximum NVMe PIIX3 Controllers: 1 Maximum NVMe ICH9 Controllers: 8 Maximum NVMe Port count: 255 Maximum Devices per NVMe Port: 1 Maximum PIIX3 Floppy Controllers:1 Maximum ICH9 Floppy Controllers: 1 Maximum Floppy Port count: 1 Maximum Devices per Floppy Port: 2 Default machine folder: C:\Users\jeff\VirtualBox VMs Raw-mode Supported: yes Exclusive HW virtualization use: off Default hard disk format: VDI VRDE auth library: VBoxAuth Webservice auth. library: VBoxAuth Remote desktop ExtPack: Log history count: 3 Default frontend: Default audio driver: DirectSound Autostart database path: Default Guest Additions ISO: C:\Program Files\Oracle\VirtualBox/VBoxGuestAdditions.iso Logging Level: all 2025-01-21 01:47:58 (14028): Command: VBoxManage -q list hostinfo Exit Code: 0 Output: Host Information: Host time: 2025-01-21T06:47:57.856000000Z Processor online count: 5 Processor count: 5 Processor online core count: 5 Processor core count: 5 Processor supports HW virtualization: yes Processor supports PAE: yes Processor supports long mode: yes Processor supports nested paging: yes Processor#0 speed: unknown Processor#0 description: AMD Phenom(tm) II X6 1090T Processor Processor#1 speed: unknown Processor#1 description: AMD Phenom(tm) II X6 1090T Processor Processor#2 speed: unknown Processor#2 description: AMD Phenom(tm) II X6 1090T Processor Processor#3 speed: unknown Processor#3 description: AMD Phenom(tm) II X6 1090T Processor Processor#4 speed: unknown Processor#4 description: AMD Phenom(tm) II X6 1090T Processor Memory size: 16126 MByte Memory available: 10601 MByte Operating system: Windows 10 Operating system version: 10.0.19045 2025-01-21 01:47:58 (14028): Command: VBoxManage -q showvminfo "boinc_6fc358c34099f3b7" --machinereadable Exit Code: -2135228415 Output: VBoxManage.exe: error: Could not find a registered machine named 'boinc_6fc358c34099f3b7' VBoxManage.exe: error: Details: code VBOX_E_OBJECT_NOT_FOUND (0x80bb0001), component VirtualBoxWrap, interface IVirtualBox, callee IUnknown VBoxManage.exe: error: Context: "FindMachine(Bstr(VMNameOrUuid).raw(), machine.asOutParam())" at line 2834 of file VBoxManageInfo.cpp 2025-01-21 01:47:58 (14028): Command: VBoxManage -q createvm --name "boinc_6fc358c34099f3b7" --basefolder "C:\ProgramData\BOINC\slots\0" --ostype "Linux26_64" --register Exit Code: 0 Output: Virtual machine 'boinc_6fc358c34099f3b7' is created and registered. UUID: 79142154-dcb1-43f8-8921-71cc04e69e31 Settings file: 'C:\ProgramData\BOINC\slots\0\boinc_6fc358c34099f3b7\boinc_6fc358c34099f3b7.vbox' 2025-01-21 01:47:58 (14028): Command: VBoxManage -q modifyvm "boinc_6fc358c34099f3b7" --description "Theory_2773-2990768-367_0" Exit Code: 0 Output: 2025-01-21 01:47:59 (14028): Command: VBoxManage -q modifyvm "boinc_6fc358c34099f3b7" --memory 630 Exit Code: 0 Output: 2025-01-21 01:47:59 (14028): Command: VBoxManage -q modifyvm "boinc_6fc358c34099f3b7" --cpus 1 Exit Code: 0 Output: 2025-01-21 01:47:59 (14028): Command: VBoxManage -q modifyvm "boinc_6fc358c34099f3b7" --acpi on --ioapic on --rtcuseutc off Exit Code: 0 Output: 2025-01-21 01:48:00 (14028): Command: VBoxManage -q modifyvm "boinc_6fc358c34099f3b7" --vram 16 --graphicscontroller VBoxVGA Exit Code: 0 Output: 2025-01-21 01:48:00 (14028): Command: VBoxManage -q modifyvm "boinc_6fc358c34099f3b7" --boot1 disk --boot2 dvd --boot3 none --boot4 none Exit Code: 0 Output: 2025-01-21 01:48:00 (14028): Command: VBoxManage -q modifyvm "boinc_6fc358c34099f3b7" --nic1 nat --natdnsproxy1 on --cableconnected1 off Exit Code: 0 Output: 2025-01-21 01:48:00 (14028): Command: VBoxManage -q modifyvm "boinc_6fc358c34099f3b7" --cableconnected1 on Exit Code: 0 Output: 2025-01-21 01:48:01 (14028): Command: VBoxManage -q modifyvm "boinc_6fc358c34099f3b7" --usb off Exit Code: 0 Output: 2025-01-21 01:48:01 (14028): Command: VBoxManage -q modifyvm "boinc_6fc358c34099f3b7" --uart1 off --uart2 off Exit Code: 0 Output: 2025-01-21 01:48:01 (14028): Command: VBoxManage -q modifyvm "boinc_6fc358c34099f3b7" --lpt1 off --lpt2 off Exit Code: 0 Output: 2025-01-21 01:48:02 (14028): Command: VBoxManage -q modifyvm "boinc_6fc358c34099f3b7" --audio none Exit Code: 0 Output: 2025-01-21 01:48:02 (14028): Command: VBoxManage -q modifyvm "boinc_6fc358c34099f3b7" --clipboard disabled Exit Code: 0 Output: 2025-01-21 01:48:02 (14028): Command: VBoxManage -q modifyvm "boinc_6fc358c34099f3b7" --draganddrop disabled Exit Code: 0 Output: 2025-01-21 01:48:02 (14028): Command: VBoxManage -q storagectl "boinc_6fc358c34099f3b7" --name "Hard Disk Controller" --add "sata" --controller "IntelAHCI" --hostiocache off --portcount 3 Exit Code: 0 Output: 2025-01-21 01:48:03 (14028): Command: VBoxManage -q showhdinfo "C:\ProgramData\BOINC/projects/lhcathome.cern.ch_lhcathome/Theory_2025_01_16_prod.vdi" Exit Code: 0 Output: UUID: 6a4110e9-e559-4c1c-bfd2-ba6f6aaf4169 Parent UUID: base State: created Type: normal (base) Location: C:\ProgramData\BOINC\projects\lhcathome.cern.ch_lhcathome\Theory_2025_01_16_prod.vdi Storage format: VDI Format variant: dynamic default Capacity: 20480 MBytes Size on disk: 781 MBytes Encryption: disabled 2025-01-21 01:48:03 (14028): Command: VBoxManage -q storageattach "boinc_6fc358c34099f3b7" --storagectl "Hard Disk Controller" --port 0 --device 0 --type hdd --medium "C:\ProgramData\BOINC/projects/lhcathome.cern.ch_lhcathome/Theory_2025_01_16_prod.vdi" Exit Code: 0 Output: 2025-01-21 01:48:03 (14028): Command: VBoxManage -q storageattach "boinc_6fc358c34099f3b7" --storagectl "Hard Disk Controller" --port 0 --device 0 --type hdd --medium none Exit Code: 0 Output: 2025-01-21 01:48:04 (14028): Command: VBoxManage -q storageattach "boinc_6fc358c34099f3b7" --storagectl "Hard Disk Controller" --port 0 --device 0 --type hdd --mtype multiattach --medium "C:\ProgramData\BOINC/projects/lhcathome.cern.ch_lhcathome/Theory_2025_01_16_prod.vdi" Exit Code: 0 Output: 2025-01-21 01:48:04 (14028): Command: VBoxManage -q storageattach "boinc_6fc358c34099f3b7" --storagectl "Hard Disk Controller" --port 1 --device 0 --type dvddrive --medium "C:\Program Files\Oracle\VirtualBox/VBoxGuestAdditions.iso" Exit Code: 0 Output: 2025-01-21 01:48:04 (14028): Command: VBoxManage -q bandwidthctl "boinc_6fc358c34099f3b7" add "boinc_6fc358c34099f3b7_net" --type network --limit 1024G Exit Code: 0 Output: 2025-01-21 01:48:05 (14028): Command: VBoxManage -q modifyvm "boinc_6fc358c34099f3b7" --natpf1 ",tcp,127.0.0.1,61521,,80" Exit Code: 0 Output: 2025-01-21 01:48:05 (14028): Command: VBoxManage -q list extpacks Exit Code: 0 Output: Extension Packs: 0 2025-01-21 01:48:06 (14028): Command: VBoxManage -q sharedfolder add "boinc_6fc358c34099f3b7" --name "shared" --hostpath "C:\ProgramData\BOINC\slots\0/shared" Exit Code: 0 Output: 2025-01-21 01:48:08 (14028): Command: VBoxManage -q startvm "boinc_6fc358c34099f3b7" --type headless Exit Code: -1073741819 Output: Waiting for VM "boinc_6fc358c34099f3b7" to power on... VBoxManage.exe: error: The virtual machine 'boinc_6fc358c34099f3b7' has terminated unexpectedly during startup with exit code -1073741819 (0xc0000005) VBoxManage.exe: error: Details: code E_FAIL (0x80004005), component MachineWrap, interface IMachine 2025-01-21 01:48:08 (14028): Command: VBoxManage -q snapshot "boinc_6fc358c34099f3b7" list Exit Code: -108 Output: This machine does not have any snapshots 2025-01-21 01:48:08 (14028): Command: VBoxManage -q bandwidthctl "boinc_6fc358c34099f3b7" remove "boinc_6fc358c34099f3b7_net" Exit Code: 0 Output: 2025-01-21 01:48:09 (14028): Command: VBoxManage -q unregistervm "boinc_6fc358c34099f3b7" --delete Exit Code: 0 Output: 0%...10%...20%...30%...40%...50%...60%...70%...80%...90%...100% 2025-01-21 01:48:14 (14028): called boinc_finish(-1073741819) </stderr_txt> ]]>
©2025 CERN