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  • systemd management using systemctl and journalctl to check systemd logs

    systemd is like the service manager for your Centos and other modern Linux distributions (including Debian/Mint/Ubuntu) allows you to enable services, stop them, restart them, check their status and even reboot your system. The key commands or arguments you will use with systemctl are the following: Unit Commands:   list-units [PATTERN...]         List loaded units &nbs........
  • Centos 7 - How To Install NFS and Mount Remotely

    1.) First install nfs-utils [root@bcitcourse ~]# yum -y install nfs-utils Loaded plugins: fastestmirror base                                                         &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........
  • error: Could not locate RPC credentials. No authentication cookie could be found, and no rpcpassword is set in the configuration file Bitcoin Litecoin Error

    error: Could not locate RPC credentials. No authentication cookie could be found, and no rpcpassword is set in the configuration file This is usually because the .cookie file cannot be read by the user you are running Litecoin or Bitcoin client/daemon as. You can adjust the permissions of the file so that the user or group they are apart of has read permissions.  ........
  • Linux Mint Install Netboot PXE Guide Howto

    *Update so this doesn't work it must be something to do with the path of nfs or something else but the installer fails with "Installer crashed" at the end whereas with the CD/USB it works. This assumes you've already installed and configured a separate PXE/DHCP server somewhere else and your /tftpboot directory is setup. This is for Linux Mint 18.1 but generally applies to most versions although you may have tro change things like "casper"........
  • drbd won't create device if previous partition is on it Command 'drbdmeta 0 v08 /dev/md160 internal create-md' terminated with exit code 40

    This is what fixed it: [root@box13 ~]# dd if=/dev/zero of=/dev/md160 bs=512 count=500 Basically you need to wipe out more than just the 512 byte partition table so 512 bytes * 500 is more than enough to make DRBD happy and think the partition is now empty. The reason this happens is because it gets confused when there is a previous partition with data on the device you are using.   root@box13 ~]# d........
  • Dell Perc 6/i Restore BIOS/Bricked Solution Guide Howto

    I bricked one of my cards by following a guide from UNRAID. Step #1 from them wipes out the BIOS, but guess what?  The step where you restore the BIOS should have been done first, which is sas2flash but no version supports or is able to find my Perc 6/i.  So now I'm a bit stuck. I tried using megarec but it's funny that it can wipe the BIOS but can't forcefully reload it: megarec -writesbr 0 mpt2sas.rom Supports 1078 control........
  • pxe-32 tftp open timeout

    pxe-32 tftp open timeout   The solution was to enable tftp in xinetd with "chkconfig tftp on". See the troubleshooting below:   chkconfig --list NetworkManager     0:off    1:off    2:off    3:off    4:off    5:off    6:off acpid              0:off&n........
  • Centos how to upgrade from PHP 5.2 to 5.3 without downtime

    This may sound silly but there will be conflicts/issues with the default Centos repository so you have to use a third party like remi (I prefer not to do this but it's the only option unless you migrate your sites/data to another server or can stand some downtime-not an option IMHO on a production server). You may need to upgrade to PHP 5.3 to run Joomla or many other reasons. Your host needs to use PHP 5.2.4 or higher to run this version of Jo........
  • Drupal 6.2 Install and how to move install to root/non-subdirectory

    drup 6.2 install $cd drupgoodinst3883/ [ drupgoodinst3883]$ ls CHANGELOG.txt  cron.php  index.php          INSTALL.pgsql.txt  INSTALL.txt  MAINTAINERS.txt  modules   robots.txt  sites   update.php   xmlrpc.php COPYRIGHT.txt  includes  INSTALL.mysql.txt  install.php        LICENSE.txt  misc  &........
  • Linux High IOWAIT updatedb can't be killed and crash with mdadm

    high IO wait   424 root      39  19  1900  848  552 D  0.0  0.0   0:00.91 updatedb root       424  0.0  0.0   1900   848 ?        DN   Mar11   0:00 /usr/bin/updatedb -f sysfs?rootfs?bdev?proc?cpuset?binfmt_misc?debugfs?sockfs?usbfs?pipefs?anon_inodefs?futexfs?tmpfs?inotifyfs?eventp........
  • PHP cannot access /usr/bin/openssl

    PHP cannot access /usr/bin/opensslI have verified the username that runs the process is able to access /usr/bin/openssl and it does exist but the PHP script is saying it doesn't exist: [code:1:1fd0f3abbe] if (!file_exists($OPENSSL)) { //echo "ERROR: OPENSSL $OPENSSL not foundn"; }[/code:1:1fd0f3abbe] I don't get itI can clearly see the contents of /usr/bin by using the PHP system fu........
  • Basic Port Listing

    Basic Port ListingHopefully someone finds this useful or at least interesting. http://www.sans.org/top20/#u9 Name Port Protocol Description Small services <20 tcp/udp small services FTP 21 tcp file transfer SSH 22 tcp login service TELNET 23 tcp login service SMTP 25 tcp mail TIME 37 tcp/udp time synchronization WINS 42 tcp/udp WINS replication DNS 53 udp naming service........
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