I am running Kubuntu 24.04 with kernel 6.17.0-14-generic on a ThinkPad T480. Until today, my ThinkPad Type 40A9 dock's USB hub worked perfectly with my laptop.

Today I applied the following security updates when prompted:

Start-Date: 2026-03-12 10:01:59 Commandline: packagekit role='update-packages' Requested-By: Me (1000) Upgrade: libcurl4-openssl-dev:amd64 (8.5.0-2ubuntu10.7, 8.5.0-2ubuntu10.8), libgtk-4-common:amd64 (4.14.5+ds-0ubuntu0.7, 4.14.5+ds-0ubuntu0.9), libfreetype6:amd64 (2.13.2+dfsg-1build3, 2.13.2+dfsg-1ubuntu0.1), libcurl3t64-gnutls:amd64 (8.5.0-2ubuntu10.7, 8.5.0-2ubuntu10.8), libcurl4t64:amd64 (8.5.0-2ubuntu10.7, 8.5.0-2ubuntu10.8), libgtk-4-1:amd64 (4.14.5+ds-0ubuntu0.7, 4.14.5+ds-0ubuntu0.9), libfreetype-dev:amd64 (2.13.2+dfsg-1build3, 2.13.2+dfsg-1ubuntu0.1), curl:amd64 (8.5.0-2ubuntu10.7, 8.5.0-2ubuntu10.8), libgtk-4-bin:amd64 (4.14.5+ds-0ubuntu0.7, 4.14.5+ds-0ubuntu0.9), libgtk-4-media-gstreamer:amd64 (4.14.5+ds-0ubuntu0.7, 4.14.5+ds-0ubuntu0.9) End-Date: 2026-03-12 10:02:03

Now the dock display output and charging still work, but usb devices are usually not recognized, or work for a short amount of time before becoming unresponsive again:

With the external wired keyboard and wireless mouse connected to the laptop directly:

 me@my-laptop:~$ lsusb
    Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
    Bus 001 Device 002: ID 046a:c092 CHERRY CHERRY Wireless Device
    Bus 001 Device 004: ID 058f:9540 Alcor Micro Corp. AU9540 Smartcard Reader
    Bus 001 Device 009: ID 8087:0a2b Intel Corp. Bluetooth wireless interface
    Bus 001 Device 010: ID 13d3:56a6 IMC Networks Integrated Camera
    Bus 001 Device 011: ID 06cb:009a Synaptics, Inc. Metallica MIS Touch Fingerprint Reader
    Bus 001 Device 020: ID 046a:c12a CHERRY CHERRY USB KEYBOARD
    Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
    Bus 002 Device 002: ID 0bda:0316 Realtek Semiconductor Corp. Card Reader
    Bus 002 Device 003: ID 17ef:101f Lenovo 
    Bus 002 Device 004: ID 17ef:1020 Lenovo ThinkPad Dock Hub
    Bus 002 Device 005: ID 17ef:3062 Lenovo ThinkPad Dock Ethernet [Realtek RTL8153B]
    Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
    Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub

with the wired keyboard connected to the dock, and the wireless mouse attached directly to the laptop:

lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 002: ID 046a:c092 CHERRY CHERRY Wireless Device
Bus 001 Device 004: ID 058f:9540 Alcor Micro Corp. AU9540 Smartcard Reader
Bus 001 Device 009: ID 8087:0a2b Intel Corp. Bluetooth wireless interface
Bus 001 Device 010: ID 13d3:56a6 IMC Networks Integrated Camera
Bus 001 Device 011: ID 06cb:009a Synaptics, Inc. Metallica MIS Touch Fingerprint Reader
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 002 Device 002: ID 0bda:0316 Realtek Semiconductor Corp. Card Reader
Bus 002 Device 003: ID 17ef:101f Lenovo 
Bus 002 Device 004: ID 17ef:1020 Lenovo ThinkPad Dock Hub
Bus 002 Device 005: ID 17ef:3062 Lenovo ThinkPad Dock Ethernet [Realtek RTL8153B]
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub

I have already disabled USB autosuspend:

   cat /sys/module/usbcore/parameters/autosuspend
   -1

What to try further?

I am using Ubuntu 20.04 with Cronopete 4.13.0 as my backup software. This has worked without issue for a number of years. I have 485GB of space left of 984GB on my backup hard disc.

Every time the back up runs I get an error message similar to the following. How can I cure this?

Starting backup

Backing up folder /home/xxxx/

Excluding folder /home/xxxx/.cache/

Excluding folder /home/xxxx/.*

Syncing disk

Syncing disk

Deleting old backup 2026_01_16_11:38:13_1768563493

<span foreground="#FF7F00">WARNING:</span> Failed to delete old backup 2026_01_16_11:38:13_1768563493: Error renaming file /media/xxxx/7cf1182d-4c41-4a68-839a-8f5f1bd815321/cronopete/xxxx/2026_01_16_11:38:13_1768563493: Bad message

Backup done. Elapsed time: 0:45

Screenshot of proc folder 140.7 TB:

It is bigger than my 250 GB hard drive. How can a folder be bigger than the hard drive's capacity?

I would like to know why when i try to run unattended-upgrades -v it is showing all the packages are blacklisted. i tried to check if any packages held using showhold command but nothing came up.

This is my current configuration for 50unattended-upgrades

Unattended-Upgrade::Allowed-Origins {
        "${distro_id}:${distro_codename}";
        "${distro_id}:${distro_codename}-security";       
        "${distro_id}ESMApps:${distro_codename}-apps-security";
        "${distro_id}ESM:${distro_codename}-infra-security";
        //"${distro_id}:${distro_codename}-updates";
        //"${distro_id}:${distro_codename}-proposed";
        //"${distro_id}:${distro_codename}-backports";
};

I am running Ubuntu 24.04. I installed VirtualBox by following these instructions.

Here are the error messages that I receive when launching my Windows VM:

VT-x is being used by another hypervisor (VERR_VMX_IN_VMX_ROOT_MODE).
VirtualBox can't operate in VMX root mode. Please disable the KVM kernel extension, recompile your kernel and reboot (VERR_VMX_IN_VMX_ROOT_MODE).
Result Code:
NS_ERROR_FAILURE (0x80004005)
Component:
ConsoleWrap
Interface:
IConsole {...}

EDIT lsmod | grep -i kvm doesn't return anything.

I am on Ubuntu 24.04. I would like to upgrade to 24.10. I had Prompt=lts set in /etc/update-manager/release-upgrades, so upon running do-release-upgrade, it said that there were no available upgrades and that to change it to Prompt=normal in order to upgrade my release. I did so, but this time it gave me a message about 25.10. I am not interested in upgrading to 25.10, I want to upgrade to 24.10. Does that message mean that I can only upgrade to 25.10? How can I make it upgrade to 24.10 instead?

I just booted and I'm getting this fuzzy and unreadable window. I'm not sure what to do.

I've been having issues with my machine not detecting my second GPU (both RTX 3090s). This is not a new machine and is an issue that popped up a few weeks ago, which I resolved by rolling back to an older kernel (unknown version). But after a recent update, I lost that kernel and am stuck with this issue.

Here's what I've tried so far:

• Swapping GPUs in their PCI slots to rule out a hardware issue
• Update to latest mobo BIOS
• Fresh 22.04 install for each driver install below
• Every NVIDIA CUDA install (>= 11.7) from the NVIDIA downloads page (deb local, deb network and run file)
• Every Ubuntu nvidia-driver* as far back as I can go to maintain a minimum CUDA version of 11.7
• Rolling back to an abritrarily old kernel version (5.15) using mainline
• Rolling forward to kernel 6.4
• Booting with a HDMI monitor attached to GPU 2

*Note that all older Ubuntu nvidia-drivers-5XX are transitional packages to either 525 or 535 (apt search nvidia-driver). The last driver I had both GPUs working was 515.

The single GPU that is listed (also my display GPU) does run CUDA workloads, but seems to make my system unstable/laggy when the job (PyTorch) starts for a few mins.

❯ uname -r
5.19.0-46-generic

❯ lspci | grep VGA
09:00.0 VGA compatible controller: NVIDIA Corporation GA102 [GeForce RTX 3090] (rev a1)
43:00.0 VGA compatible controller: NVIDIA Corporation GA102 [GeForce RTX 3090] (rev a1)

❯ nvidia-smi
Sat Jul  1 12:11:41 2023       
+-----------------------------------------------------------------------------+
| NVIDIA-SMI 525.125.06   Driver Version: 525.125.06   CUDA Version: 12.0     |
|-------------------------------+----------------------+----------------------+
| GPU  Name        Persistence-M| Bus-Id        Disp.A | Volatile Uncorr. ECC |
| Fan  Temp  Perf  Pwr:Usage/Cap|         Memory-Usage | GPU-Util  Compute M. |
|                               |                      |               MIG M. |
|===============================+======================+======================|
|   0  NVIDIA GeForce ...  Off  | 00000000:43:00.0  On |                  N/A |
|  0%   41C    P8    24W / 350W |    562MiB / 24576MiB |      0%      Default |
|                               |                      |                  N/A |
+-------------------------------+----------------------+----------------------+
                                                                               
+-----------------------------------------------------------------------------+
| Processes:                                                                  |
|  GPU   GI   CI        PID   Type   Process name                  GPU Memory |
|        ID   ID                                                   Usage      |
|=============================================================================|
|    0   N/A  N/A      1879      G   /usr/lib/xorg/Xorg                140MiB |
|    0   N/A  N/A      2338    C+G   ...ome-remote-desktop-daemon      258MiB |
|    0   N/A  N/A      2375      G   /usr/bin/gnome-shell               87MiB |
|    0   N/A  N/A      3338      G   ...566776601308618822,262144       73MiB |
+-----------------------------------------------------------------------------+

dmesg Link to GitHub Gist

The weird thing is very occasionally, after a fresh CUDA install (not isolated to a single driver version) and a restart, the 2nd GPU does show up in nvidia-smi. But after a reboot is disappears again. Uninstalling and reinstalling CUDA can replicate this but it appears to be random (and not what I want to do each time I reboot)

Any ideas how I can get my machine working properly again?

Link to nvidia-bug-report

I installed Ubuntu 22.04 two weeks ago. I started using Ubuntu, and it was all fine until two weeks ago. In one day I logged out and came back, and the Setting icons were missing.

I'm having a kernel panic in VirtualBox 6.1.32, with Ubuntu 18.04. Windows 11 21H2 build 20000.675.

I tried the "Try Ubuntu without installing", option, but it doesn't reach any prompt (#). I reset the BIOS factory defaults. I disabled Hyper-V. I tried the recovery options, but it also kernel panics. I cannot even do a fresh install.

I followed these steps and tried a fresh install like here .

The last time I was playing around with it was BIOS features to install Ubuntu native on W11 under a SSD with secure boot enabled, and BitLocker. I remember I moved Secure Boot options, but nothing for BitLocker.

Does anyone have any idea why this could be happening?

I have a USB-to-RS232 converter cable, the cable is proven to work in Windows machines, Ubuntu detects it but does not attach the converter to any /dev/tty.

I tried connecting it to USB 2.0 and 3.0, nothing.

Does not sow any error or anything.

The OS is Ubuntu 20.04, Kernel: 5.4.0-66-generic running on a 10th gen Intel i5, 8GB DDR4 RAM, Aorus ULTRA Z490I

"dmesg" tells me that it is in the system, but it's not attached to anything.

[12811.723685] usb 1-4: new full-speed USB device number 8 using xhci_hcd
[12811.872472] usb 1-4: New USB device found, idVendor=067b, idProduct=23c3, bcdDevice= 3.05
[12811.872474] usb 1-4: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[12811.872474] usb 1-4: Product: USB-Serial Controller
[12811.872475] usb 1-4: Manufacturer: Prolific Technology Inc.
[12811.872476] usb 1-4: SerialNumber: EFA>f103Y23

"lsusb" shows that it is in fact detected

Bus 001 Device 008: ID 067b:23c3 Prolific Technology, Inc. USB-Serial Controller

"usb-devices" shows this:

T:  Bus=01 Lev=01 Prnt=01 Port=03 Cnt=04 Dev#=  8 Spd=12  MxCh= 0
D:  Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
P:  Vendor=067b ProdID=23c3 Rev=03.05
S:  Manufacturer=Prolific Technology Inc.
S:  Product=USB-Serial Controller
S:  SerialNumber=EFA>f103Y23
C:  #Ifs= 1 Cfg#= 1 Atr=a0 MxPwr=100mA
I:  If#=0x0 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=(none)

Edit:

I have an Ubuntu Laptop (It's the same Windows machine as tested it before but booted into Ubuntu) with same OS and Kernel, dmesg shows that It is detected and attached to ttyUSB0

[   77.810199] usb 3-2: new full-speed USB device number 5 using xhci_hcd
[   77.959158] usb 3-2: New USB device found, idVendor=067b, idProduct=23c3, bcdDevice= 3.05
[   77.959163] usb 3-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[   77.959166] usb 3-2: Product: USB-Serial Controller 
[   77.959169] usb 3-2: Manufacturer: Prolific Technology Inc. 
[   77.959171] usb 3-2: SerialNumber: EFA>f103Y23
[   78.122784] usbcore: registered new interface driver usbserial_generic
[   78.122793] usbserial: USB Serial support registered for generic
[   78.127135] usbcore: registered new interface driver pl2303
[   78.127145] usbserial: USB Serial support registered for pl2303
[   78.127169] pl2303 3-2:1.0: pl2303 converter detected
[   78.127337] usb 3-2: pl2303 converter now attached to ttyUSB0

I am using Ubuntu 18.04 Bionic Beaver. When I tried to open an .mkv file, it showed an error message

Unable to Play the file - application/x-rar decoder is required to play the file, but is not installed.

I tried to open the file in different media players including VLC Media Player. But didn't work. And could not install that software (which mentioned in error message). What should I do?

My Ubuntu 20.04 system has been affected by occasional freezes (~ each 1-2 days) which completely blocks any interaction (not even REISUB works) and requires pressing on the power button to restart the computer. This is a brand new installation on a laptop MSI GF65 Thin 10SER. I have done some research already and this seems to be an old problem (https://linuxreviews.org/Linux_Kernel_5.5_Will_Not_Fix_The_Frequent_Intel_GPU_Hangs_In_Recent_Kernels, https://www.dedoimedo.com/computers/intel-microcode-atomic-update.html, https://hobo.house/2018/05/18/fix-for-intel-i915-gpu-freeze-on-recent-linux-kernels/) related to the Intel iGPU.

My dmesg is full of lines such as the ones below and inevitably they cause the system to freeze.

[drm:intel_pipe_update_end [i915]] *ERROR* Atomic update failure on pipe A (start=9338 end=9339) time 321 us, min 1063, max 1079, scanline start 1038, end 1090

$ uname -r

5.4.0-58-generic

$ lspci -k | grep -EA3 'VGA|3D|Display':

00:02.0 VGA compatible controller: Intel Corporation UHD Graphics (rev 05)
    DeviceName: Onboard - Video
    Subsystem: Micro-Star International Co., Ltd. [MSI] Device 12aa
    Kernel driver in use: i915
--
01:00.0 VGA compatible controller: NVIDIA Corporation TU106 [GeForce RTX 2060] (rev a1)
    Subsystem: Micro-Star International Co., Ltd. [MSI] Device 12aa
    Kernel driver in use: nvidia
    Kernel modules: nvidiafb, nouveau, nvidia_drm, nvidia

I have tried the following:

• Add the kernel options i915.enable_psr=0, i915.enable_dc=0

• Enable early KMS for the Intel graphics driver (add i915 to /etc/initramfs-tools/modules)

• Enable GuC with i915.enable_guc=2, however it isn't working as $ sudo cat /sys/kernel/debug/dri/0/i915_guc_load_status | grep status: returns status: DISABLED

• Change the X.Org display driver to modeset instead of the xserver-xorg-video-intel

• Update the linux kernel to 5.8

• Add the following to /usr/share/X11/xorg.conf.d/10-intel.conf

    Section "Device"
      Identifier "Intel Graphics"
      Driver "intel"
      Option "NoAccel" "True"
      Option "DRI" "False"
    EndSection
  

One observation is that when I change the Prime Profile to Performance mode (i.e. only the nvidia gpu is used and the intel one isn't) I don't get any of these errors in dmesg. However this isn't a solution for me since this options drains my battery very quickly.

I am a new Ubuntu user and I would really appreciate if someone could give a hand or just provide a workaround so I can have a stable system with no crashes. Let me know if you need any additional information. Thanks in advance!

Update 20/12/2020:

Setting GRUB_CMDLINE_LINUX="nouveau.modeset=0" on /etc/default/grub stopped the dmesg atomic update failure errors. However, now glxinfo|egrep "OpenGL renderer" gives OpenGL renderer string: llvmpipe (LLVM 10.0.0, 256 bits) instead of OpenGL renderer string: Mesa Intel(R) UHD Graphics (CML GT2). This is a problem because now I get extremely high CPU usage from gnome-shell. I don't really know what to take out from this information.

Help would be much appreciated.

In the meanwhile I have restored the grub configuration and done some other changes. $ inxi -G

Graphics:  Device-1: Intel UHD Graphics driver: i915 v: kernel 
           Device-2: NVIDIA TU106 [GeForce RTX 2060] driver: nvidia v: 450.80.02 
           Display: x11 server: X.Org 1.20.8 driver: modesetting,nvidia 
           resolution: 1920x1080~144Hz 
           OpenGL: renderer: Mesa Intel UHD Graphics (CML GT2) v: 4.6 Mesa 20.0.8

Update 21/12/2020:

Ok so I have been running my system with the Nvidia Prime performance profile on (I think this means the iGPU isn't being used, only the dGPU - nvidia - is) and I just got a freeze while listening to Spotify (which happens to also be one of the reasons why my computer has frozen in the past), however this time I didn't register any Atomic update error in this session and journalctl -b -1 -e didn't register anything relevant (at least for me). I will follow the answer to this question How can I tell why 20.04 is crashing? and then I will update the topic. Let me know if there's any output/ information you need to understand better the problem.

Update 23/12/2020:

I performed a memtest from https://www.memtest86.com/ and got 0 errors (results below):

I also did a clean install of Ubuntu, Mint and Manjaro. Every one of them would show the Atomic update error in dmesg. I sent the laptop for the repair service as I think the problem is due to hardware malfunction.

So the laptop came out from RMA and they told me there was nothing wrong with it. Unfortunately I had to switch to Windows as I can't afford having an unstable system like I described above. In the future I may try to install a newer version of Ubuntu to check if the problem persists.

I am getting a kernel panic Ubuntu 20.04 when trying to shutdown. Reboot somehow goes through. I tried to shut down using init 0 or from the GUI yielding the same result.

[  163.839298]  common_interrupt+0xf/0xf
[  163.839497]  <IRQ>
[  163.839749]  [I  0000: cpu_idle_enter_stat+0xc5/0x450
[  163.840053]  Code: cf e8 d1 0f 01 00 41 0f 20 c0 0f 01 f8 65 8b 2d 77 12 79 4c 44 00 f6 c4 02 0f 85 05 03 00 00 31 ff e8 02 7a 07 00 f0 66 0f  1f 44
[  163.840414]  RSP: 0018:ffffc238027b3d88 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffdb
[  163.840765]  RAX: ffff99bb2c  RDX:  4b  RDI: ffff99bb25fa05  RSI: 0000000000000004 RBX: 0000000000000000
[  163.841144]  RBP: ffffc238027b3dc0 R08: 00000000800700c0 R09: 0000000000000f62 R10: ffff99bb2f63b120
[  163.841518]  R11: 0000000000000000 R12: ffffc238027b3db8 R13: 0000000000000000 R14: 0000000000000000
[  163.841910]  R15: 0000000000000000
[  163.842186]  ? cpu_idle+0x8a/0xd0
[  163.842424]  ? cpu_startup_entry+0x24/0x80
[  163.842659]  ? call_cpuidle+0x23/0x40
[  163.842914]  ? do_idle+0x1d7/0x2b0
[  163.843209]  ? cpu_startup_entry+0x94/0x80
[  163.843473]  ? start_secondary+0xd7/0x1c0
[  163.845132]  ? secondary_startup_64+0xa4/a0
[  163.847162]  Modules linked in: btrfs xor zstd_compress raid6_pq ufosq nx4 hfsplus hfs minix ntfs msdos jfs xfs libcrc32c ccm rfcomm cmac
[  163.847379]  algif_hash algif_skcipher af_alg bnep intel_rapl_msr intel_rapl_common x86_pkg_temp_thermal intel_powerclamp coretemp snd_hda_codec_hdmi snd_hda_codec_realtek
[  163.847591]  ledtrig_audio kvm_intel kvm nis_iso8859_1 cdrom crct10dif_pclmul ghash_clmulni_intel intel_imep ath10k_pci ath10k_core aesni_intel crypto_simd cryptd mac80211
[  163.847792]  glue_helper snd_intel_dspcfg snd_intel_dspci snd_h0u snd_hda_core intel_rapl_perf dell_smbios mac80211 nouveau snd_seq_midi snd_ha_codec
[  163.847993]  usbbudio snd_usbmidi_lib snd_seq_midi_event sparse_keymap dcdbas btintel wmi_thunderbolt wmi_bmof mc cfg80211 snd_rawmidi snd_seq snd_seq_device snd_timer drm_kms_helper ecdh_generic
[  163.848195]  cdc_tcm cdc_acm typec_ucsi ucsi_acpi i2c_algo_bit bttbit mei_intel bluetooth snd_pcm fbcon bitblt fbcon tileblit softcursor font syscopyarea mei_me sysfillrect
[  163.848392]  ip_tables x_tables autofs4
[  163.848580]  soundcore psmouse i2c_i801 i2c s i2c_smbus acsyisgblt mac_hid acpi_pad sch_fq_codel parport_pc pdev lp parport drm lp_tables x_tables autofs4
[  163.848764]  i915 video i2c_algo_bit drm_kms_helper cec hid_generic r8169 uas intel_lpss alx usb_storage ahci idma64 mdio virt_dma libahci wmi video usbid hid
[  163.848979]  [last unloaded: psmouse]
[  163.850213]  CR2: 0000000000000008
[  163.850220]  ---[ end trace 36b9a3fa545f0f25 ]---
[  163.852034]  RIP: 0010:2c_do_irq_handler_master+0x21d/0x690
[  163.952203]  Code: 4c 29 c4 0f 84  micro 29 49 44 0f 8f 7d 4b 7e 24 a9 00 00 80 00 0f 84 95 da 00 00 48 09 c8 41 c1 e1 04 49 89 d1 48 89 55 c0 4d 8b 24 24 48 85
[  163.952544]  RSP: 0018: ffffc23803bc7d20 EFLAGS: 00010006
[  163.952718]  RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000014
[  163.952893]  RSI: 0000000000000092 RDI: 0000000000000000 RBP: ffffc23803bc7d78 R08: 0000000000000001
[  163.953066]  R09: 0000000000000000 R10: 0000000000000140 R11: 0000000000000000 R12: 0000000000000001
[  163.953244]  R13: ffffc23803bc7d74 R14: ffff99bb29b9c8b8 R15: ffff99bb29badbd8
[  163.953414]  ? irq_enter_rcu+0x47/0x50
[  163.953580]  ? handle_level_irq+0xfc/0x250
[  163.953746]  ? asm_sysvec_apic_timer_interrupt+0x16/0x20
[  163.953919]  ? asm_sysvec_apic_timer_interrupt+0x12/0x20
[  163.954089]  ? asm_sysvec_apic_timer_interrupt+0x12/0x20
[  163.954264]  ? asm_sysvec_apic_timer_interrupt+0x12/0x20
[  163.954434]  ? irq_exit_rcu+0x234/0x240
[  163.954600]  ? sysvec_apic_timer_interrupt+0x16/0x90
[  163.954770]  ? asm_sysvec_apic_timer_interrupt+0x12/0x20
[  163.954938]  ? irqentry_exit_to_user_mode+0x5/0x20
[  163.955109]  ? irqentry_exit+0x19/0x20
[  163.955278]  ? exc_page_fault+0xde/0x170
[  163.955448]  ? asm_exc_page_fault+0x8/0x30
[  163.955617]  ? cpu_startup_entry+0x20/0x80
[  163.955787]  ? x86_64_start_kernel+0x148/0x170
[  163.955957]  ? secondary_startup_64_no_verify+0xd5/0xdb
[  163.956132]  Modules linked in: zram
[  163.956304]  CR2: 0000000000000008
[  163.956479]  ---[ end trace 3de38381bed0a4cc ]---
[  163.956659]  RIP: 0010:2c_do_irq_handler_master+0x21d/0x690
[  163.956831]  Code: 4c 29 c4 0f 84 48 02 00 00 49 44 0f 8f 7d 4b 7e 24 a9 00 00 80 00 0f 84 95 da 00 00 48 09 c8 41 c1 e1 04 49 89 d1 48 89 55 c0 4d 8b 24 24 48 85
[  163.957007]  RSP: 0018: ffffc23802763de0 EFLAGS: 00010246
[  163.957179]  RAX: 0000000000000001 RBX: 0000000000000092 RCX: 0000000000000000 RDX: 0000000000000014
[  163.957348]  RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc23802763e38 R08: 0000000000000001
[  163.957523]  R09: 0000000000000000 R10: 0000000000000140 R11: 0000000000000000 R12: 0000000000000004
[  163.957698]  R13: ffff99bb25a65e90 R14: ffff99bb29b9cb00 R15: 0000000000000046
[  163.957869]  ? cpu_startup_entry+0x20/0x80
[  163.958039]  ? x86_64_start_kernel+0x148/0x170
[  163.958212]  ? secondary_startup_64_no_verify+0xd5/0xdb
[  163.958391]  Kernel Offset: 0x39a98000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
[  163.958632]  ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---

How to troubleshoot this error message?

Results of sudo lshw -C memory:

*-firmware                
       description: BIOS
       vendor: Alienware
       physical id: 0
       version: 1.0.21
       date: 02/25/2020
       size: 64KiB
       capacity: 16MiB
       capabilities: pci pnp upgrade shadowing cdboot bootselect edd int13floppy1200 int13floppy720 int13floppy2880 int5printscreen int14serial int17printer acpi usb biosbootspecification netboot uefi
  *-memory
       description: System Memory
       physical id: 2d
       slot: System board or motherboard
       size: 32GiB
     *-bank:0
          description: DIMM DDR4 Synchronous Unbuffered (Unregistered) 2666 MHz (0.4 ns)
          product: KHX2666C16/16G
          vendor: 00002B0C0000
          physical id: 0
          serial: 11298D68
          slot: ChannelA-DIMM0
          size: 16GiB
          width: 64 bits
          clock: 2666MHz (0.4ns)
     *-bank:1
          description: DIMM [empty]
          physical id: 1
          slot: ChannelA-DIMM1
     *-bank:2
          description: DIMM DDR4 Synchronous Unbuffered (Unregistered) 2666 MHz (0.4 ns)
          product: KHX2666C16/16G
          vendor: 00002B0C0000
          physical id: 2
          serial: 0B29EE67
          slot: ChannelB-DIMM0
          size: 16GiB
          width: 64 bits
          clock: 2666MHz (0.4ns)
     *-bank:3
          description: DIMM [empty]
          physical id: 3
          slot: ChannelB-DIMM1
  *-cache:0
       description: L1 cache
       physical id: 34
       slot: L1 Cache
       size: 384KiB
       capacity: 384KiB
       capabilities: synchronous internal write-back unified
       configuration: level=1
  *-cache:1
       description: L2 cache
       physical id: 35
       slot: L2 Cache
       size: 1536KiB
       capacity: 1536KiB
       capabilities: synchronous internal write-back unified
       configuration: level=2
  *-cache:2
       description: L3 cache
       physical id: 36
       slot: L3 Cache
       size: 9MiB
       capacity: 9MiB
       capabilities: synchronous internal write-back unified
       configuration: level=3
  *-memory UNCLAIMED
       description: Memory controller
       product: 200 Series/Z370 Chipset Family Power Management Controller
       vendor: Intel Corporation
       physical id: 1f.2
       bus info: pci@0000:00:1f.2
       version: 00
       width: 32 bits
       clock: 33MHz (30.3ns)
       configuration: latency=0
       resources: memory:ec100000-ec103fff

Lubuntu 18.04 (lxde) here, upon AMD Epyc 7282. Kernel 4.15. The system is stable and works flawlessly, but id does refuse to suspend.

If I try to suspend it, the screen blanks, but the system does not power off.

At this point, if I hit a key or move the mouse, nothing happens. If I hit the power button, the system "wakes up", presenting the login screen, and then all the applications as I left them.

Hibernation is absent alltogether.

Note that Epyc Rome is not affected by the notorious RDRAND bug which affects Ryzen 3000 and causes problems with suspend to ram.

EDIT: I used the system for days with high load, and can confirm rock stability, but if I leave it blanking the monitor, there is no way to wake it up.. One has to connect via ssh and reset the system.

EDIT(II): Example output for journalctl -u systemd-suspend.service:

gen 25 04:33:52 epyc systemd[1]: Starting Suspend...
gen 25 04:33:52 epyc systemd-sleep[1743]: Suspending system...
gen 25 04:34:36 epyc systemd-sleep[1743]: System resumed.
gen 25 04:34:36 epyc systemd-sleep[1743]: /dev/sda:
gen 25 04:34:36 epyc systemd-sleep[1743]:  setting Advanced Power Management level to 0xfe (254)
gen 25 04:34:36 epyc systemd-sleep[1743]:  APM_level        = 254

EDIT (III): I actually managed to hibernate the system using uswsusp, by specifying explicitly the resume device, that is, the swap partition:

sudo s2disk -r /dev/sda1

In such condition the system does shut down visualizing SNAPSHOTTING THE SYSTEM...

If I power on, the system does boot saying RESUMING FROM HIBERNATION... but then, it just displays the desktop, with no trace of any application left open. I will investigate the logs and report back.

I'm having a kernel panic problem (Kernel panic : not syncing attempted to kill init!) when I try to boot into Ubuntu. See image for details and specifically the part about not being able to load shared libraries.

I'm not sure how exactly this happened, but I was facing a problem with the Enter key on the keyboard (it didn't seem to be working) and I ended up rebooting a few times without much help. And then finally when I used an external keyboard and got the Enter key to work again, this kernel panic occurred.

I've looked at other related messages, but none of them seemed directly applicable here.

Before this I've had to run fsck a few times while booting.

Here are the boot messages that are reporting this issue. The kernel panic boot message appears on the next to last line.

[   16.266079] print_req_error: I/O error, dev sda, sector 458539840
[   22.340411] ata5.00: exception Emask 0x0 SAct 0x5ffe000 SErr 0x0 action 0x0
[   22.340440] ata5.00: irq_stat 0x40000008
[   22.340455] ata5.00: failed command: READ FPDMA QUEUED
[   22.340476] ata5.00: cmd 60/08:68:a8:c9:54/00:00:1b:00:00/40 tag 13 ncq dma 4096 in
[   22.340476]          res 41/40:00:a8:c9:54/00:00:1b:00:00/40 Emask 0x409 (media error) <L
[   22.340523] ata5.00: status: { DRDY ERR }
[   22.340538] ata5.00: error: { UNC }
[   22.342078] print_req_error: I/O error, dev sda, sector 458541480
/sbin/init: error while loading shared libraries: libcryptsetup.so.12: cannot open shared ob
[   35.752550] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00007f00
[   35.752550] 
[   35.752582] CPU: 0 PID: 1 Comm: init Not tainted 4.15.0-65-generic #74-Ubuntu
[   35.752605] Hardware name: LENOVO 20238/INVALID, BIOS 79CN46WW(V3.05) 12/23/2013
[   35.752628] Call Trace:
[   35.752644]  dump_stack+0x63/0x8e
[   35.752659]  panic+0xe4/0x254
[   35.752672]  do_exit+0xbba/0xbc0
[   35.752685]  do_group_exit+0x43/0xb0
[   35.752699]  SyS_exit_group+0x14/0x20
[   35.752715]  do_syscall_64+0x73/0x130
[   35.752731]  entry_SYSCALL_64_after_hwframe+0x3d/0xa2
[   35.752748] RIP: 0033:0x7f1a67913056
[   35.752761] RSP: 002b:00007ffeae1bd7d8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
[   35.752786] RAX: ffffffffffffffda RBX: 00007f1a67919ce0 RCX: 00007f1a67913056
[   35.752809] RDX: 000000000000007f RSI: 000000000000003c RDI: 000000000000007f
[   35.752831] RBP: 00007ffeae1bdf80 R08: 00000000000000e7 R09: 00007ffeae1bd294
[   35.752854] R10: 0000000000000020 R11: 0000000000000202 R12: 000000000000000d
[   35.752876] R13: 00007f1a67af3e90 R14: 00007f1a67af3e20 R15: 00007f1a67b1f170
[   35.752921] Kernel Offset: 0x1c000000 from 0xffffffff81000000 (relocation range: 0xffffffff8
[   35.752956] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x00007f00
[   35.752956]
_

If I run apt-cache show nonexistent, I get this error:

N: Unable to locate package nonexistent
E: No packages found

I know the E stands for "Error", and a W would stand for "Warning", but what does the N stand for? "Information"?

Are there other letters that may show up?

I couldn't find anything in man apt-cache, man apt, or man apt-get.

P.s. This came up because of this question: Bash file redirection bug?

ifup gets stuck, and it takes a long time at boot up and down.

me@K501L:~$ systemctl status networking.service
● networking.service - Raise network interfaces
   Loaded: loaded (/lib/systemd/system/networking.service; enabled; vendor preset: enabled)
   Active: failed (Result: timeout) since Wed 2018-08-01 13:24:54 CEST; 1h 0min ago
     Docs: man:interfaces(5)
  Process: 1049 ExecStart=/sbin/ifup -a --read-environment (code=killed, signal=TERM)

  Process: 918 ExecStartPre=/bin/sh -c [ "$CONFIGURE_INTERFACES" != "no" ] && [ -n "$(ifquery --read-environment --list --exclude=lo)" ] &&
 Main PID: 1049 (code=killed, signal=TERM)

août 01 13:19:52 K501L systemd[1]: Starting Raise network interfaces...
août 01 13:19:55 K501L ifup[1049]: check cable
août 01 13:20:00 K501L ifup[1049]: /sbin/ifup: waiting for lock on /run/network/ifstate.enp2s0
août 01 13:24:54 K501L systemd[1]: networking.service: Start operation timed out. Terminating.
août 01 13:24:54 K501L systemd[1]: networking.service: Main process exited, code=killed, status=15/TERM
août 01 13:24:54 K501L systemd[1]: networking.service: Failed with result 'timeout'.
août 01 13:24:54 K501L systemd[1]: Failed to start Raise network interfaces.

/etc/interfaces

#LAN
auto enp2s0
iface enp2s0 inet static
    address 10.0.0.2/24 
    gateway 10.0.0.1
    dns-nameserver 10.0.0.1

thougt it says it didn't raise:

2: enp2s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000

/etc/resolv.conf

# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
#     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
# 127.0.0.53 is the systemd-resolved stub resolver.
# run "systemd-resolve --status" to see details about the actual nameservers.
nameserver 10.0.0.1
nameserver 127.0.0.53

it works if i remove this line from /etc/interfaces

dns-nameserver 10.0.0.1

I updated 7 packages on my Linux server 'apport libexpat1 linux-generic linux-headers-generic linux-image-generic python3-apport python3-problem-repore'. After the update, when I reboot the system, it has a kernel panic.

I think the problem is with the version. When I ran the kernel 4.4.0-62 from grub loader it worked fine, but when I loaded with 4.4.0-83 it showed kernel panic.

Now I have to press Shift every time I start my computer to load the previous kernel, but I don't want to keep doing this. I would like to uninstall the updated kernel or select the previous kernel as default.

I need to grep last 5 minutes log. log file:

18-06-17 06:00:09 ID-5
18-06-17 06:00:11 ID-78
20-06-17 09:34:51 ID-Hello
21-06-17 09:20:49 link is down
22-06-17 06:00:11 ID-674
22-06-17 06:40:51 ID-2
22-06-17 06:40:55 ID-7
22-06-17 06:40:16 ID-3
22-06-17 06:42:20 ID-2

date +"%d-%m-%y %k:%M:%S"
22-06-17 06:43:40

I tried:

awk -v date=$(date -d "30 minutes ago" +"%d-%m-%y %k:%M:%S") '$1" "$2 >= date { print $0 }' log

but have the error:

awk: cmd. line:1: 06:43:40
awk: cmd. line-1-   ^ syntax error

Can you please help me with this problem?

This is really weird. Sometimes, seemingly without any good reason a bunch of processes named cc1 will pop up and consume all my CPU causing my ubuntu to nearly freeze. After 10-15 seconds those processes disappear again. Does anyone have an idea what's happening?

I googled and it seems that cc1 has to do with the gcc compiler, but I'm not compiling anything. Last time it happened was after a fresh reboot with only Chrome and Terminal running (plus some background processes, such as Dropbox).

Help would be much appreciated!

I tried an unsuccessful installation of Oracle 12C on Ubuntu 16.04.1 64 bits several times. Typically, I get the error:

Error in invoking target 'all_no_rcl' of makefile '.../rdbms/ins_rdbms.mk'.
See '....log' for details.

After today's upgrade of Ubuntu 16.04 I made restart and received a "Kernel panic" during the system load attempt.

Is it possible to fix/recover it or required to reinstall Ubuntu from the ground up? If possible to recover, could you walk me through it?

Last message:

End Kernel panic - not syncing: Attempted to kill init! exit code=0x00007f00 

I wanted to create a WiFi hotspot on my Ubuntu 16.04 with mt7601usb WiFi adapter. I cloned and compiled the mt7601uap driver from here which is supposed to be a Ralink Wireless Adapter Access Point Driver only, but after rebooting I'm stuck with a kernel panic.

/dev/sda1: recovering journal
/dev/sda1: clean, 269427/6320160 files, 2050344/25231360 blocks
[   25.830069] BUG: unable to handle kernel NULL pointer dereference at           (null)
[   25.830192] IP: [<ffffffffc0639f9b>] RTUSBBulkRxComplete+0x1b/0x40 [mt7601Uap]
[   25.830344] PGD 0
[   25.830377] Oops: 0000 [#1] SMP
[   25.830431] Modules linked in: rtnet7601Uap(OE) mt7601Uap(POE) rtutil7601Uap(OE) btusb btrtl btbcm btintel bluetooth kvm_amd kvm snd_hda_codec_realtek snd_hda
_codec_generic snd_hda_intel snd_hda_codec snd_hda_core irqbypass snd_hwdep snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq input_leds snd_seq_devi
ce serio_raw snd_timer k8temp snd soundcore edac_mce_amd edac_core 8250_fintek i2c_piix4 shpchp mac_hid parport_pc ppdev lp parport autofs4 pata_acpi hid_generi
c usbhid hid amdkfd amd_iommu_v2 radeon i2c_algo_bit ttm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops pata_atiixp drm r8169 ahci mii libahci fje
[   25.831441] CPU: 1 PID: 0 Comm: swapper/1 Tainted: P           OE   4.4.0-30-generic #49-Ubuntu
[   25.831548] Hardware name: MICRO-STAR INTERNATIONAL CO., LTD MS-7327/MS-7327, BIOS V1.6 02/28/2008
[   25.831659] task: ffff880074ce8000 ti: ffff880074ce4000 task.ti: ffff880074ce4000
[   25.831752] RIP: 0010: [<ffffffffc0639f9b>]  [<ffffffffc0639f9b>] RTUSBBulkRxComplete+0x1b/0x40 [mt7601Uap]
[   25.831898] RSP: 0018:ffff880077d03e38  EFLAGS: 00010082
[   25.831964] RAX: 0000000000000000 RBX: ffff880073fd0b40 RCX: 0000000000000002
[   25.832051] RDX: 0000000000000000 RSI: ffff880073fd0b40 RDI: ffff880073fd0b40
[   25.832139] RBP: ffff880077d03e48 R08: 0000000000000000 R09: 000000000000a020
[   25.832227] R10: 0000000000000000 R11: ffff8800359481e0 R12: ffff880073fd0b40
[   25.832316] R13: ffff88003585e000 R14: 0000000000000000 R15: 0000000000000000
[   25.832404] FS:  00007f8712abf780(0000) GS:ffff880077d00000(0000) knlGS:0000000000000000
[   25.832504] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[   25.832575] CR2: 0000000000000000 CR3: 00000000711b7000 CR4: 00000000000006e0
[   25.832663] Stack:
[   25.832692]  ffff880073fd0b40 0000000000000282 ffff880077d03e58 ffffffffc02c871f
[   25.832802]  ffff880077d03e88 ffffffff81614f95 ffff880077d03e98 ffff88003585e1e0
[   25.832913]  ffff88003585e1dc ffff88003585e1d8 ffff880077d03ed0 ffffffff8161598d
[   25.833024] Call Trace:
[   25.833056]  <IRQ> 
[   25.833089]  [<ffffffffc02c871f>] RTUSBBulkRxComplete+0xf/0x20 [rtnet7601Uap]
[   25.833187]  [<ffffffff81614f95>] __usb_hcd_giveback_urb+0x85/0x130
[   25.833266]  [<ffffffff8161598d>] usb_giveback_urb_bh+0x9d/0x100
[   25.833344]  [<ffffffff8108554b>] tasklet_action+0xfb/0x110
[   25.833416]  [<ffffffff81085b51>] __do_softirq+0x101/0x290
[   25.833486]  [<ffffffff81085e59>] irq_exit+0x89/0x90
[   25.833553]  [<ffffffff81830524>] do_IRQ+0x54/0xda
[   25.833615]  [<ffffffff8182e602>] common_interrupt+0x82/0x82
[   25.833687]  <EOI> 
[   25.833717]  [<ffffffff810645e6>] ? native_safe_halt+0x6/0x10
[   25.833795]  [<ffffffff81039dfe>] default_idle+0x1e/0xe0
[   25.833864]  [<ffffffff81039f0b>] amd_e400_idle+0x4b/0x100
[   25.833935]  [<ffffffff8103990f>] arch_cpu_idle+0xf/0x20
[   25.834005]  [<ffffffff810c3f9a>] default_idle_call+0x2a/0x40
[   25.834039]  [<ffffffff810c4301>] cpu_startup_entry+0x2f1/0x350
[   25.834039]  [<ffffffff81051714>] start_secondary+0x154/0x190
[   25.834039] Code: ce ff eb c4 66 90 66 2e 0f 1f 84 00 00 00 00 00 66 66 66 66 90 55 48 89 e5 41 54 53 49 89 fc e8 2c 87 ce ff 48 8b 40 08 4c 89 e6 <48> 8b 18 
48 83 c3 d8 48 89 df e8 ae ce ff 48 89 df e8 4e ae 
[   25.834039] RIP  [<ffffffffc0639f9b>] RTUSBBulkRxComplete+0x1b/0x40 [mt7601Uap]
[   25.834039]  RSP <ffff880077d03e38>
[   25.834039] CR2: 0000000000000000
[   25.834039] ---[ end trace 740f85aa664a908d ]---
[   25.834039] Kernel panic - not syncing: Fatal exception in interrupt
[   25.834039] Kernel Offset: disabled
[   25.834039] ---[ end Kernel panic - not syncing: Fatal exception in interrupt

Removing the USB and rebooting and blacklisting the driver works, but I need the driver to setup a WiFi hotspot. Do you have any suggestions?

Can I get list, or a link to a list, of all the categories I could put for a desktop icon when creating one? Specifically I would like my icon to show up in the Games lens, but I'm curious as to all the available categories. Running Ubuntu 14.04.

I had to abort a backup of my system because it stalled on the file /proc/kcore. I check its size and, well, the file is enormous. Checking Google, it seems that many other people have absurdly large kcore files as well.

I have three questions:

1. should I be concerned about kcore's size?
2. if so, how can I reduce its size?
3. is there any reason to backup the /proc/ directory?

I have not been able to print or scan with my Epson Style Office BX305F on Ubuntu. I've tried adding a printer and using simple scan but neither work.

Since when I installed netatalk on Ubuntu server 14.04 I get a kernel panic at boot. I think netatalk is the cause because I can see the word "appletalk" many times in the kernel panic screen. I've also changed both my RAM modules and checked my HDD, CPU and GPU to be sure that the kernel panic was not caused by a hardware failure. I tried booting with a different kernel and the situation didn't change, while booting in rescue mode didn't result in a kernel panic. However, I got a kernel panic even in rescue mode after issuing the dpkg --configure -a command.

I really don't know what to do and I don't understand much from the kernel panic screen. Here it is. I hope you can help me.

[   32.452016] RDX: 00000000000000fe RSI: 0000000000000300 RDI: ffff88003ab57400
[   32.452016] RBP: ffff88003fc03d38 R08: 000000000000009b R09: 0000000000000000
[   32.452016] R10: 0000000000000014 R11: ffffffff81639f20 R12: ffff88003ab7cb00
[   32.452016] R13: 0000000000000006 R14: 0000000000000000 R15: 00000000000000ff
[   32.452016] FS:  00007f85af2e7740(0000) GS:ffff88003fc00000(0000) knlGS:0000000000000000
[   32.452016] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   32.452016] CR2: 00007f85b1236000 CR3: 000000003b7df000 CR4: 00000000000007f0
[   32.452016] Stack:
[   32.452016]  ffff88003fc03d70 ffffffff81607621 ffff88003aa67016 ffff88003ab7cb00
[   32.452016]  ffff88003ab57400 0000000000000006 0000000000000000 ffff88003fc03db8
[   32.452016]  ffffffffa0302fc8 ffff8800366a0be0 ffff88003fc03e9c ffff88003ab7cb00
[   32.452016] Call Trace:
[   32.452016]  <IRQ>
[   32.452016]  [<ffffffff81607621>] sock_queue_rcv_skb+0x181/0x220
[   32.452016]  [<ffffffffa0302fc8>] atalk_rcv+0x268/0x4b0 [appletalk]
[   32.452016]  [<ffffffffa02f7244>] snap_rcv+0x74/0xb1 [psnap]
[   32.452016]  [<ffffffffa032851e>] llc_rcv+0x29e/0x370 [llc]
[   32.452016]  [<ffffffff8161a906>] __netif_receive_skb_core+0x666/0x840
[   32.452016]  [<ffffffff8161aaf8>] __netif_receive_skb+0x18/0x60
[   32.452016]  [<ffffffff8161b61e>] process_backlog+0xae/0x1a0
[   32.452016]  [<ffffffff8161aee2>] net_rx_action+0x152/0x250
[   32.452016]  [<ffffffff8106caec>] __do_softirq+0xec/0x2c0
[   32.452016]  [<ffffffff81727edc>] do_softirq_own_stack+0x1c/0x30
[   32.452016]  <EOI>
[   32.452016]  [<ffffffff8106cd65>] do_softirq+0x55/0x60
[   32.452016]  [<ffffffff8106cdf4>] local_bh_enable+0x84/0x90
[   32.452016]  [<ffffffff8161c5bd>] __dev_queue_xmit+0x9d/0x500
[   32.452016]  [<ffffffff8161ca30>] ? dev_queue_xmit+0x10/0x20
[   32.452016]  [<ffffffff81639f4b>] ? eth_header+0x2b/0xd0
[   32.452016]  [<ffffffff8161ca30>] dev_queue_xmit+0x10/0x20
[   32.452016]  [<ffffffffa0328705>] llc_build_and_send_ui_pkt+0x85/0x8e [llc]
[   32.452016]  [<ffffffffa02f70a9>] snap_request+0x49/0x60 [psnap]
[   32.452016]  [<ffffffffa030264b>] atalk_sendmsg+0x4cb/0x660 [appletalk]
[   32.452016]  [<ffffffff8160254b>] sock_sendmsg+0x8b/0xc0
[   32.452016]  [<ffffffff8101b763>] ? native_sched_clock+0x13/0x80
[   32.452016]  [<ffffffff816026f1>] SYSC_sendto+0x121/0x1c0
[   32.452016]  [<ffffffff8109dd84>] ? vtime_account_user+0x54/0x60
[   32.452016]  [<ffffffff81020d35>] ? syscall_trace_enter+0x145/0x250
[   32.452016]  [<ffffffff816031fe>] SyS_sendto+0xe/0x10
[   32.452016]  [<ffffffff817266bf>] tracesys+0xe1/0xe6
[   32.452016] Code: f9 1f 76 16 31 d2 39 c1 7e 08 02 14 07 48 ff c0 eb f4 31 c0 84 d2 48 0f 44 c7 5d c3 0f 1f 44 00 00 55 48 89 
e5 0f 0b 55 48 89 e5 <0f> 0b 0f 1f 44 00 00 55 48 c7 c0 ec db a7 81 41 89 f0 48 89 ce
[   32.452016] RIP  [<ffffffff81718886>] skb_orphan.part.24+0x4/0x6
[   32.452016]  RSP <ffff88003fc03d38>
[   32.537202] ---[ end trace fac7d34ae366228a ]---
[   32.539770] Kernel panic - not syncing: Fatal exception in interrupt
[   32.541147] drm_kms_helper: panic occurred, switching back to text console
_

I've got a X.509 certificate file (with a .der file extension) of a certificate authority that I want to trust (it's required to connect to my academic network). When I double-click on a .der file I can either import that certificate to the Gnome2 Key Storage or User Key Storage (by the way, what's the difference between those two?).

My question is, where these certificates are stored? I've check /etc/ssl/certs folder but I couldn't find the one that I've just imported. Also, how I can manage certificates after being imported (list them and remove)?

I have a comic strip book in cbr (Calibre?) format. How can I convert it to pdf in my Ubuntu 12.04? I tried to install calibre hoping that it is able to do so. But it seems to be buggy and does not show up. Appreciate your hints to do the conversion.