• Linux What is umask (user mask) for file and directory creation permissions and how to calculate umask and change the defaults

    umask are the default permissions that are applied when a file or directory are created. To see this in action simply just "touch filename" or "mkdir somedir" and you'll see what default permissions are applied. The first thing Ialways tell people you should know is to NEVER change the defaults unless you are making them more restrictive. But they work well and if you change the defaults you could end up creating a file without permission to read........
  • wodim / cdrecord error cannot burn DVD or BDR .iso Errno: 5 (Input/output error), write_g1 scsi sendcmd: no error

    dvd+rw-mediainfo /dev/sr0 INQUIRY: [ASUS ][BW-16D1HT ][3.00] GET [CURRENT] CONFIGURATION: Mounted Media: 11h, DVD-R Sequential Media ID: RITEKF1&n........
  • Linux Mint Black Screen after boot no graphics solution

    This is not the normal "black screen"issue and I was shocked to eventually find out why. The normal advice of reconfiguring Xorg didn't work. Even booting into "Recovery Mode" did not help. Here is the short end of the stick that fixed it: sudo apt-get install mdm mate-desktop-environment Yes you got it right, mdm and the mate-desktop-environment / gnome were somehow uninstalled. This must be whe........
  • Authentication refused: bad ownership or modes for directory /home/user SSH Public Key Authentication Failed Solution

    First of all I got this error after accidentally messing up my usergroup by using usermod -G user group When I would login using SSHkeys it would fail: sshd[2020]: Authentication refused: bad ownership or modes for directory /home/one No worries, the fix is simple! chmod g-w /home/use........
  • Nvidia Linux Mint/Ubuntu screentearing horizontal line solution

    Finally after ages I found the solution which is on many pages on the net but not obvious and should have been standard or more common info! Instant Solution: Type this into the terminal (unfortunately the driver config menu doesn't have the option as itis hidden): nvidia-settings --assign CurrentMetaMode="nvidia-auto-select +0+0 { ForceCompositionPipeline = On }" Make permanent Cli........
  • Track 01: 34 of 1726 MB written (fifo 100%) [buf 99%] 3.6x.Errno: 5 (Input/output error), write_g1 scsi sendcmd: cmd timeout after 1.897 (40) s CDB: 2A 00 00 00 44 A9 00 00 1F 00 resid: 6144 cmd finished after 1.897s timeout 40s write track da

    These errors believe it or not are simply because of not being the root user or running with sudo! However if you didn't know to try as root you'd think there was a problem with your burner or disc Essentially it looks like without root you cannot send the required scsi commands to continue writing. Ithink cdrecord should have built-in tests or safeguards to see if it has the permissions to run the required commands. I guess for more advanced users the idea is simila........
  • sshd[10470]: Authentication refused: bad ownership or modes for directory /root

    This can be a case of bad permissions or modes as the error says. Normally one would assume permissions but often a script may change ownership of /root to something else. This was the case half the time I've encountered this. So in short make sure ownership is correct chown -R root.root /root........
  • Linux check NIC ethernet port network card speed

    ethtool eth0 Settings for eth0: Supported ports: [ TP MII ] Supported link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full ........
  • OpenVZ mismatched kernel and dev when compiling.

    ./configure ./configure: line 91: cd: /lib/modules/2.6.32-042stab084.25/build: No such file or directory Error: kernel version not found. Please make sure your kernel is configured. dr-xr-xr-x. 4 root root 4096 Feb 21 06:13 .. lrwxrwxrwx 1 root root 45 Feb 21 06:13 build -> ../../../usr/src/kernels/2.6.32-042stab084.25 drwxr-xr-x 2 root root 4096 Feb 12 20........
  • How To Burn ISO Image using cdrtools/dvdrtools for Linux/Unix Ubuntu/Debian/RHEL/Centos etc..

    It really is as simple as: cdrecord -v dev=/dev/sr0 pathtoyourisoimage.iso -v is for verbose, I prefer it but if you don't you won't see as much output like below (I like to know the details and exactly what's happening) dev=/dev/sr0 specifies the device name of your burner (they say not to use it and to specify some weird annoying device string but using the raw /dev has always worked for me and is how it should have been implemented from the start IMHO)........
  • sshd[9217]: Authentication refused: bad ownership or modes for file /root/.ssh/authorized_keys

    sshd[9217]: Authentication refused: bad ownership or modes for file /root/.ssh/authorized_keys I made sure the entire .ssh subdir is owned by the user root (this is root's account); chown -R root.root .ssh chmod 600 .ssh/authorized_keys but it still doesn't work and gives me the same message sshd[7339]: Authentication refused: bad ownership or modes for directory /root chmod 700 /root........
  • Linux Kernel Boot Black Screen of Death Freeze/Halt Solution

    This happens on some systems due to a video issue with Intel Videocards, after you see the kernel load you may see almost immediately that you get a black screen. The following kernel parameters usually solve it: nomodeset i915.modeset=0 xforcevesa some people just use "nomodeset" and others use "i915.modeset=0". I think nomodeset may also do the same for each video driver so it may imply i915.modeset=0 anyway but I am not sure.........
  • Linux Kernel Freeze/Hang during boot on io scheduler cfq registered (default)

    You'll see the following and the boot process will freeze: io scheduler noop registered io scheduler anticipatory registered io scheduler deadline registered io scheduler cfq registered (default) I have struggled with this issue on vari........
  • Linux Burn MP3 CD On the Fly using

    I finally decided to look into some utils that did this, and the first one I found is "mp3burn". It is unbelievable simple and perfect. *2017-11 update and mp3burn is still available in standard repos such as Ubuntu 14/16 so this is a current and working project. Just install the package and it gets all required libraries to convert and then burn's on the fly. And you won't believe how simple it is. I just want to a directory that had the MP3's I wanted t........
  • Linux Unix Xorg X Server Intel Extreme i810 Graphics Problem

    Linux Unix Xorg X Server Intel Extreme i810 Graphics Problem(EE) I810(0): No Video BIOS modes for chosen depth. (EE) Screen(s) found, but none have a usable configuration. I have a new Dell PC with one of the latest Intel Extreme Graphics on-board crap. From what I can see any Linux/Unix/FreeBSD versions running XFree86 or Xorg from years ago or the latest version today will have this problem. It's easily corrected FOR MOST people. Go into your........
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