| Name | ecdad6c9b713_0 |
| Workunit | 240985651 |
| Created | 28 Apr 2026, 17:24:52 UTC |
| Sent | 28 Apr 2026, 19:36:22 UTC |
| Report deadline | 6 May 2026, 19:36:22 UTC |
| Received | 28 Apr 2026, 20:37:01 UTC |
| Server state | Over |
| Outcome | Computation error |
| Client state | Compute error |
| Exit status | -2147467259 (0x80004005) Unknown error code |
| Computer ID | 10650368 |
| Run time | 23 sec |
| CPU time | 0 sec |
| Priority | 28 |
| Validate state | Invalid |
| Credit | 0.00 |
| Device peak FLOPS | 53.07 GFLOPS |
| Application version | ATLAS Simulation v3.03 (vbox64_mt_mcore_atlas) windows_x86_64 |
| Peak working set size | 9.94 MB |
| Peak swap size | 1.98 MB |
| Peak disk usage | 251.27 MB |
<core_client_version>8.2.9</core_client_version>
<![CDATA[
<message>
Erreur non sp�cifi�e
(0x80004005) - exit code 2147500037 (0x80004005)</message>
<stderr_txt>
2026-04-28 21:37:41 (10996): vboxwrapper version 26210
2026-04-28 21:37:41 (10996): BOINC client version: 8.2.9
2026-04-28 21:37:42 (10996): Detected: VirtualBox VboxManage Interface (Version: 7.2.8)
2026-04-28 21:37:42 (10996): Successfully copied 'init_data.xml' to the shared directory.
2026-04-28 21:37:42 (10996): Create VM. (boinc_450dadf06dec2263, slot#13)
2026-04-28 21:37:43 (10996): Setting Memory Size for VM. (4800MB)
2026-04-28 21:37:43 (10996): Setting CPU Count for VM. (8)
2026-04-28 21:37:43 (10996): Setting Chipset Options for VM.
2026-04-28 21:37:44 (10996): Setting Graphics Controller Options for VM. (Driver: VBoxVGA, 16MB)
2026-04-28 21:37:44 (10996): Setting Boot Options for VM.
2026-04-28 21:37:44 (10996): Setting Network Configuration for NAT. (Driver: virtio)
2026-04-28 21:37:45 (10996): Enabling VM Network Access.
2026-04-28 21:37:45 (10996): Disabling USB Support for VM.
2026-04-28 21:37:45 (10996): Disabling COM Port Support for VM.
2026-04-28 21:37:45 (10996): Disabling LPT Port Support for VM.
2026-04-28 21:37:46 (10996): Disabling Audio Support for VM.
2026-04-28 21:37:46 (10996): Disabling Clipboard Support for VM.
2026-04-28 21:37:46 (10996): Disabling Drag and Drop Support for VM.
2026-04-28 21:37:47 (10996): Adding storage controller(s) to VM.
2026-04-28 21:37:47 (10996): Adding virtual disk drive to VM. (ATLAS_vbox_3.03_image.vdi)
2026-04-28 21:37:49 (10996): Adding VirtualBox Guest Additions to VM.
2026-04-28 21:37:49 (10996): Adding network bandwidth throttle group to VM. (Defaulting to 1024GB)
2026-04-28 21:37:49 (10996): forwarding host port 49514 to guest port 80
2026-04-28 21:37:50 (10996): Enabling remote desktop for VM.
2026-04-28 21:37:50 (10996): Required extension pack not installed, remote desktop not enabled.
2026-04-28 21:37:50 (10996): Enabling shared directory for VM.
2026-04-28 21:37:51 (10996): Starting VM using VBoxManage interface. (boinc_450dadf06dec2263, slot#13)
2026-04-28 21:37:55 (10996): Error in start VM for VM: -2147467259
Command:
VBoxManage -q startvm "boinc_450dadf06dec2263" --type headless
Output:
VBoxManage.exe: error: Not in a hypervisor partition (HVP=0) (VERR_NEM_NOT_AVAILABLE).
VBoxManage.exe: error: VT-x is disabled in the BIOS for all CPU modes (VERR_VMX_MSR_ALL_VMX_DISABLED)
VBoxManage.exe: error: Details: code E_FAIL (0x80004005), component ConsoleWrap, interface IConsole
Waiting for VM "boinc_450dadf06dec2263" to power on...
2026-04-28 21:37:55 (10996): VM failed to start.
2026-04-28 21:37:55 (10996): Could not start
2026-04-28 21:37:55 (10996): ERROR: VM failed to start
2026-04-28 21:37:55 (10996): Powering off VM.
2026-04-28 21:37:55 (10996): Deregistering VM. (boinc_450dadf06dec2263, slot#13)
2026-04-28 21:37:55 (10996): Removing network bandwidth throttle group from VM.
2026-04-28 21:37:55 (10996): Removing VM from VirtualBox.
Hypervisor System Log:
00:00:07.342433 Saving settings file "C:\Users\nutte\.VirtualBox\VirtualBox.xml" with version "1.12-windows"
00:00:07.378894 Finished saving settings file "C:\Users\nutte\.VirtualBox\VirtualBox.xml"
00:00:07.379387 Saving settings file "C:\ProgramData\BOINC\slots\13\boinc_450dadf06dec2263\boinc_450dadf06dec2263.vbox" with version "1.19-windows"
00:00:07.381255 Finished saving settings file "C:\ProgramData\BOINC\slots\13\boinc_450dadf06dec2263\boinc_450dadf06dec2263.vbox"
00:00:07.603581 Platform architecture set to 'x86'
00:00:07.606275 Saving settings file "C:\ProgramData\BOINC\slots\13\boinc_450dadf06dec2263\boinc_450dadf06dec2263.vbox" with version "1.19-windows"
00:00:07.644586 Finished saving settings file "C:\ProgramData\BOINC\slots\13\boinc_450dadf06dec2263\boinc_450dadf06dec2263.vbox"
00:00:07.868803 Platform architecture set to 'x86'
00:00:07.870909 ERROR [COM]: aRC=VBOX_E_OBJECT_NOT_FOUND (0x80bb0001) aIID={e36a5081-a82a-40bd-9e4e-42a44d6ce50f} aComponent={SessionMachine} aText={No storage device attached to device slot 0 on port 0 of controller 'Hard Disk Controller'}, preserve=false aResultDetail=0
00:00:07.871527 Saving settings file "C:\ProgramData\BOINC\slots\13\boinc_450dadf06dec2263\boinc_450dadf06dec2263.vbox" with version "1.19-windows"
00:00:07.873791 Finished saving settings file "C:\ProgramData\BOINC\slots\13\boinc_450dadf06dec2263\boinc_450dadf06dec2263.vbox"
00:00:07.873950 ERROR [COM]: aRC=VBOX_E_OBJECT_NOT_FOUND (0x80bb0001) aIID={e36a5081-a82a-40bd-9e4e-42a44d6ce50f} aComponent={SessionMachine} aText={No storage device attached to device slot 0 on port 0 of controller 'Hard Disk Controller'}, preserve=false aResultDetail=0
00:00:07.875653 Saving settings file "C:\ProgramData\BOINC\slots\13\boinc_450dadf06dec2263\boinc_450dadf06dec2263.vbox" with version "1.19-windows"
00:00:07.877855 Finished saving settings file "C:\ProgramData\BOINC\slots\13\boinc_450dadf06dec2263\boinc_450dadf06dec2263.vbox"
00:00:07.878349 Saving settings file "C:\ProgramData\BOINC\slots\13\boinc_450dadf06dec2263\boinc_450dadf06dec2263.vbox" with version "1.19-windows"
00:00:07.880685 Finished saving settings file "C:\ProgramData\BOINC\slots\13\boinc_450dadf06dec2263\boinc_450dadf06dec2263.vbox"
00:00:08.140840 Platform architecture set to 'x86'
00:00:08.142903 ERROR [COM]: aRC=VBOX_E_OBJECT_NOT_FOUND (0x80bb0001) aIID={e36a5081-a82a-40bd-9e4e-42a44d6ce50f} aComponent={SessionMachine} aText={No storage device attached to device slot 0 on port 1 of controller 'Hard Disk Controller'}, preserve=false aResultDetail=0
00:00:08.144672 ERROR [COM]: aRC=VBOX_E_OBJECT_NOT_FOUND (0x80bb0001) aIID={e36a5081-a82a-40bd-9e4e-42a44d6ce50f} aComponent={SessionMachine} aText={No storage device attached to device slot 0 on port 1 of controller 'Hard Disk Controller'}, preserve=false aResultDetail=0
00:00:08.144860 Saving settings file "C:\Users\nutte\.VirtualBox\VirtualBox.xml" with version "1.12-windows"
00:00:08.181376 Finished saving settings file "C:\Users\nutte\.VirtualBox\VirtualBox.xml"
00:00:08.181672 Saving settings file "C:\Users\nutte\.VirtualBox\VirtualBox.xml" with version "1.12-windows"
00:00:08.183857 Finished saving settings file "C:\Users\nutte\.VirtualBox\VirtualBox.xml"
00:00:08.184215 Saving settings file "C:\ProgramData\BOINC\slots\13\boinc_450dadf06dec2263\boinc_450dadf06dec2263.vbox" with version "1.19-windows"
00:00:08.185990 Finished saving settings file "C:\ProgramData\BOINC\slots\13\boinc_450dadf06dec2263\boinc_450dadf06dec2263.vbox"
00:00:08.409703 Platform architecture set to 'x86'
00:00:08.411200 Saving settings file "C:\ProgramData\BOINC\slots\13\boinc_450dadf06dec2263\boinc_450dadf06dec2263.vbox" with version "1.19-windows"
00:00:08.447598 Finished saving settings file "C:\ProgramData\BOINC\slots\13\boinc_450dadf06dec2263\boinc_450dadf06dec2263.vbox"
00:00:08.682466 Platform architecture set to 'x86'
00:00:08.684499 Saving settings file "C:\ProgramData\BOINC\slots\13\boinc_450dadf06dec2263\boinc_450dadf06dec2263.vbox" with version "1.19-windows"
00:00:08.720569 Finished saving settings file "C:\ProgramData\BOINC\slots\13\boinc_450dadf06dec2263\boinc_450dadf06dec2263.vbox"
00:00:09.212493 Platform architecture set to 'x86'
00:00:09.213750 Saving settings file "C:\ProgramData\BOINC\slots\13\boinc_450dadf06dec2263\boinc_450dadf06dec2263.vbox" with version "1.19-windows"
00:00:09.249774 Finished saving settings file "C:\ProgramData\BOINC\slots\13\boinc_450dadf06dec2263\boinc_450dadf06dec2263.vbox"
00:00:09.476768 Platform architecture set to 'x86'
00:00:09.478378 ERROR [COM]: aRC=VBOX_E_NOT_SUPPORTED (0x80bb0009) aIID={e36a5081-a82a-40bd-9e4e-42a44d6ce50f} aComponent={SessionMachine} aText={This VM is not encrypted}, preserve=false aResultDetail=0
00:00:09.484991 ERROR [COM]: aRC=VBOX_E_OBJECT_NOT_FOUND (0x80bb0001) aIID={e36a5081-a82a-40bd-9e4e-42a44d6ce50f} aComponent={SessionMachine} aText={No storage device attached to device slot 0 on port 2 of controller 'Hard Disk Controller'}, preserve=false aResultDetail=0
00:00:09.485075 ERROR [COM]: aRC=VBOX_E_OBJECT_NOT_FOUND (0x80bb0001) aIID={e36a5081-a82a-40bd-9e4e-42a44d6ce50f} aComponent={SessionMachine} aText={No storage device attached to device slot 0 on port 2 of controller 'Hard Disk Controller'}, preserve=false aResultDetail=0
00:00:09.492395 ERROR [COM]: aRC=E_FAIL (0x80004005) aIID={83cfdc66-4f20-4569-ad39-8722f7d472b3} aComponent={RecordingSettingsWrap} aText={Recording not started}, preserve=false aResultDetail=0
00:00:09.493407 ERROR [COM]: aRC=E_FAIL (0x80004005) aIID={e36a5081-a82a-40bd-9e4e-42a44d6ce50f} aComponent={SessionMachine} aText={This machine does not have any snapshots}, preserve=false aResultDetail=0
00:00:09.756280 Launched VM: 632178944 pid: 2920 (0xb68) frontend: headless name: boinc_450dadf06dec2263
00:00:13.406889 Platform architecture set to 'x86'
00:00:14.133784 Saving settings file "C:\ProgramData\BOINC\slots\13\boinc_450dadf06dec2263\boinc_450dadf06dec2263.vbox" with version "1.19-windows"
00:00:14.170388 Finished saving settings file "C:\ProgramData\BOINC\slots\13\boinc_450dadf06dec2263\boinc_450dadf06dec2263.vbox"
00:00:14.232477 ERROR [COM]: aRC=E_FAIL (0x80004005) aIID={e36a5081-a82a-40bd-9e4e-42a44d6ce50f} aComponent={SessionMachine} aText={This machine does not have any snapshots}, preserve=false aResultDetail=0
00:00:14.541966 ERROR [COM]: aRC=VBOX_E_INVALID_OBJECT_STATE (0x80bb0007) aIID={e36a5081-a82a-40bd-9e4e-42a44d6ce50f} aComponent={MachineWrap} aText={Cannot unregister the machine 'boinc_450dadf06dec2263' while it is locked}, preserve=false aResultDetail=0
00:00:15.820420 Saving settings file "C:\Users\nutte\.VirtualBox\VirtualBox.xml" with version "1.12-windows"
00:00:15.833557 Finished saving settings file "C:\Users\nutte\.VirtualBox\VirtualBox.xml"
00:00:15.833679 Saving settings file "C:\Users\nutte\.VirtualBox\VirtualBox.xml" with version "1.12-windows"
00:00:15.843758 Finished saving settings file "C:\Users\nutte\.VirtualBox\VirtualBox.xml"
00:00:15.844916 DeleteVM Saving settings file "C:\Users\nutte\.VirtualBox\VirtualBox.xml" with version "1.12-windows"
00:00:15.847425 DeleteVM Finished saving settings file "C:\Users\nutte\.VirtualBox\VirtualBox.xml"
00:00:20.857512 main VirtualBox: object deletion starts
00:00:20.858931 main HostDnsMonitor: shutting down ...
00:00:20.859022 main HostDnsMonitor: shut down
00:00:20.861775 Watcher ERROR [COM]: aRC=E_ACCESSDENIED (0x80070005) aIID={2ce10519-3c09-45d8-a12d-e887786146b7} aComponent={VirtualBoxWrap} aText={The object is not ready}, preserve=false aResultDetail=0
00:00:20.862068 main VirtualBox: object deleted
VM Execution Log:
VM Startup Log:
VM Trace Log:
rec_screen_video_enabled="on"
rec_screen_audio_enabled="off"
rec_screen_dest="File"
rec_screen_dest_filename="C:\\ProgramData\\BOINC\\slots\\13\\boinc_450dadf06dec2263\\boinc_450dadf06dec2263-screen0.webm"
rec_screen_opts="ac_profile=med"
rec_screen_video_res_xy="1024x768"
rec_screen_video_rate_kbps=512
rec_screen_video_fps=25
description="ecdad6c9b713_0"
GuestMemoryBalloon=0
2026-04-28 21:37:45 (10996):
Command: VBoxManage -q modifyvm "boinc_450dadf06dec2263" --nic1 nat --nic-type1 "virtio" --cable-connected1 off --nat-dns-proxy1 on
Exit Code: 0
Output:
2026-04-28 21:37:45 (10996):
Command: VBoxManage -q modifyvm "boinc_450dadf06dec2263" --cable-connected1 on
Exit Code: 0
Output:
2026-04-28 21:37:45 (10996):
Command: VBoxManage -q modifyvm "boinc_450dadf06dec2263" --usb off
Exit Code: 0
Output:
2026-04-28 21:37:45 (10996):
Command: VBoxManage -q modifyvm "boinc_450dadf06dec2263" --uart1 off --uart2 off
Exit Code: 0
Output:
2026-04-28 21:37:46 (10996):
Command: VBoxManage -q modifyvm "boinc_450dadf06dec2263" --lpt1 off --lpt2 off
Exit Code: 0
Output:
2026-04-28 21:37:46 (10996):
Command: VBoxManage -q modifyvm "boinc_450dadf06dec2263" --audio-enabled off
Exit Code: 0
Output:
2026-04-28 21:37:46 (10996):
Command: VBoxManage -q modifyvm "boinc_450dadf06dec2263" --clipboard disabled
Exit Code: 0
Output:
2026-04-28 21:37:47 (10996):
Command: VBoxManage -q modifyvm "boinc_450dadf06dec2263" --draganddrop disabled
Exit Code: 0
Output:
2026-04-28 21:37:47 (10996):
Command: VBoxManage -q storagectl "boinc_450dadf06dec2263" --name "Hard Disk Controller" --add "sata" --controller "IntelAHCI" --hostiocache off --portcount 3
Exit Code: 0
Output:
2026-04-28 21:37:47 (10996):
Command: VBoxManage -q showhdinfo "C:\ProgramData\BOINC/projects/lhcathome.cern.ch_lhcathome/ATLAS_vbox_3.03_image.vdi"
Exit Code: 0
Output:
UUID: 3e56213b-898f-4e83-899f-8eb541d45260
Parent UUID: base
State: created
Type: multiattach
Location: C:\ProgramData\BOINC\projects\lhcathome.cern.ch_lhcathome\ATLAS_vbox_3.03_image.vdi
Storage format: VDI
Format variant: dynamic default
Capacity: 20480 MBytes
Size on disk: 4204 MBytes
Encryption: disabled
Property: AllocationBlockSize=1048576
2026-04-28 21:37:47 (10996):
Command: VBoxManage -q storageattach "boinc_450dadf06dec2263" --storagectl "Hard Disk Controller" --port 0 --device 0 --type hdd --mtype multiattach --medium "C:\ProgramData\BOINC/projects/lhcathome.cern.ch_lhcathome/ATLAS_vbox_3.03_image.vdi"
Exit Code: -2135228409
Output:
VBoxManage.exe: error: Cannot attach medium 'C:\ProgramData\BOINC\projects\lhcathome.cern.ch_lhcathome\ATLAS_vbox_3.03_image.vdi': the media type 'MultiAttach' can only be attached to machines that were created with VirtualBox 4.0 or later
VBoxManage.exe: error: Details: code VBOX_E_INVALID_OBJECT_STATE (0x80bb0007), component SessionMachine, interface IMachine, callee IUnknown
VBoxManage.exe: error: Context: "AttachDevice(Bstr(pszCtl).raw(), port, device, DeviceType_HardDisk, pMedium2Mount)" at line 786 of file VBoxManageStorageController.cpp
2026-04-28 21:37:48 (10996):
Command: VBoxManage -q showhdinfo "C:\ProgramData\BOINC/projects/lhcathome.cern.ch_lhcathome/ATLAS_vbox_3.03_image.vdi"
Exit Code: 0
Output:
UUID: 3e56213b-898f-4e83-899f-8eb541d45260
Parent UUID: base
State: created
Type: multiattach
Location: C:\ProgramData\BOINC\projects\lhcathome.cern.ch_lhcathome\ATLAS_vbox_3.03_image.vdi
Storage format: VDI
Format variant: dynamic default
Capacity: 20480 MBytes
Size on disk: 4204 MBytes
Encryption: disabled
Property: AllocationBlockSize=1048576
2026-04-28 21:37:48 (10996):
Command: VBoxManage -q closemedium disk "C:\ProgramData\BOINC\projects\lhcathome.cern.ch_lhcathome\ATLAS_vbox_3.03_image.vdi"
Exit Code: 0
Output:
2026-04-28 21:37:48 (10996):
Command: VBoxManage -q showhdinfo "C:\ProgramData\BOINC/projects/lhcathome.cern.ch_lhcathome/ATLAS_vbox_3.03_image.vdi"
Exit Code: 0
Output:
UUID: 3e56213b-898f-4e83-899f-8eb541d45260
Parent UUID: base
State: created
Type: normal (base)
Location: C:\ProgramData\BOINC\projects\lhcathome.cern.ch_lhcathome\ATLAS_vbox_3.03_image.vdi
Storage format: VDI
Format variant: dynamic default
Capacity: 20480 MBytes
Size on disk: 4204 MBytes
Encryption: disabled
Property: AllocationBlockSize=1048576
2026-04-28 21:37:48 (10996):
Command: VBoxManage -q storageattach "boinc_450dadf06dec2263" --storagectl "Hard Disk Controller" --port 0 --device 0 --type hdd --medium "C:\ProgramData\BOINC/projects/lhcathome.cern.ch_lhcathome/ATLAS_vbox_3.03_image.vdi"
Exit Code: 0
Output:
2026-04-28 21:37:49 (10996):
Command: VBoxManage -q storageattach "boinc_450dadf06dec2263" --storagectl "Hard Disk Controller" --port 0 --device 0 --type hdd --medium none
Exit Code: 0
Output:
2026-04-28 21:37:49 (10996):
Command: VBoxManage -q storageattach "boinc_450dadf06dec2263" --storagectl "Hard Disk Controller" --port 0 --device 0 --type hdd --mtype multiattach --medium "C:\ProgramData\BOINC/projects/lhcathome.cern.ch_lhcathome/ATLAS_vbox_3.03_image.vdi"
Exit Code: 0
Output:
2026-04-28 21:37:49 (10996):
Command: VBoxManage -q storageattach "boinc_450dadf06dec2263" --storagectl "Hard Disk Controller" --port 1 --device 0 --type dvddrive --medium "C:\Program Files\Oracle\VirtualBox/VBoxGuestAdditions.iso"
Exit Code: 0
Output:
2026-04-28 21:37:49 (10996):
Command: VBoxManage -q bandwidthctl "boinc_450dadf06dec2263" add "boinc_450dadf06dec2263_net" --type network --limit 1024G
Exit Code: 0
Output:
2026-04-28 21:37:50 (10996):
Command: VBoxManage -q modifyvm "boinc_450dadf06dec2263" --natpf1 ",tcp,127.0.0.1,49514,,80"
Exit Code: 0
Output:
2026-04-28 21:37:50 (10996):
Command: VBoxManage -q list extpacks
Exit Code: 0
Output:
Extension Packs: 1
Pack no. 0: Oracle VirtualBox Extension Pack
Version: 7.2.8
Revision: 173730
Edition:
Description: Oracle Cloud Infrastructure integration, PXE ROM.
VRDE Module:
Crypto Module:
Usable: true
Why unusable:
2026-04-28 21:37:50 (10996):
Command: VBoxManage -q sharedfolder add "boinc_450dadf06dec2263" --name "shared" --hostpath "C:\ProgramData\BOINC\slots\13/shared"
Exit Code: 0
Output:
2026-04-28 21:37:55 (10996):
Command: VBoxManage -q startvm "boinc_450dadf06dec2263" --type headless
Exit Code: -2147467259
Output:
VBoxManage.exe: error: Not in a hypervisor partition (HVP=0) (VERR_NEM_NOT_AVAILABLE).
VBoxManage.exe: error: VT-x is disabled in the BIOS for all CPU modes (VERR_VMX_MSR_ALL_VMX_DISABLED)
VBoxManage.exe: error: Details: code E_FAIL (0x80004005), component ConsoleWrap, interface IConsole
Waiting for VM "boinc_450dadf06dec2263" to power on...
2026-04-28 21:37:55 (10996):
Command: VBoxManage -q snapshot "boinc_450dadf06dec2263" list
Exit Code: -108
Output:
This machine does not have any snapshots
2026-04-28 21:37:55 (10996):
Command: VBoxManage -q bandwidthctl "boinc_450dadf06dec2263" remove "boinc_450dadf06dec2263_net"
Exit Code: 0
Output:
VBoxManage.exe: error: Bandwidth groups cannot be deleted while the VM is running
2026-04-28 21:37:56 (10996):
Command: VBoxManage -q unregistervm "boinc_450dadf06dec2263" --delete
Exit Code: -2135228409
Output:
VBoxManage.exe: error: Cannot unregister the machine 'boinc_450dadf06dec2263' while it is locked
VBoxManage.exe: error: Details: code VBOX_E_INVALID_OBJECT_STATE (0x80bb0007), component MachineWrap, interface IMachine, callee IUnknown
VBoxManage.exe: error: Context: "Unregister(fDeleteAll ? CleanupMode_DetachAllReturnHardDisksAndVMRemovable :CleanupMode_DetachAllReturnHardDisksOnly, ComSafeArrayAsOutParam(aMedia))" at line 235 of file VBoxManageMisc.cpp
2026-04-28 21:37:57 (10996):
Command: VBoxManage -q unregistervm "boinc_450dadf06dec2263" --delete
Exit Code: 0
Output:
0%...10%...20%...30%...40%...50%...60%...70%...80%...90%...100%
2026-04-28 21:38:02 (10996): called boinc_finish(-2147467259)
</stderr_txt>
]]>
©2026 CERN