• ssh how to verify your host key / avoid MIM attacks


    SSH helps keep us secure in many ways, one of those is the host-key fingerprint which is unique. If you have been connecting to an SSH server that you've made no changes to and suddenly ssh warns that the key doesn't match then you have a problem. But how about connecting to an existing server for the first time on a new machine or client? A lot of new clients calculate it using an SHA256 hash but it is not as easy on your host machine to produce the sam........
  • Cisco Unified Communications Manager 12 Install Errors on Proxmox/KVM


    The strange thing is that usually the first install or two will work on any new machine but then it suddenly won't. I had this experience on QEMU 2.13 on a different machine. There is something finicky or buggy about the CUCM installer even when choosing the same virtual hardware specs. qemu-kvm command: /usr/libexec/qemu-kvm -version QEMU PC emulator version 0.12.1 (qemu-kvm-0.12.1.2-2.506.el6_10.1), Copyright (c) 2003-2008 Fabrice Bellard ........
  • Linux Mint XWindows Ubuntu MATE or Cinnamon How To Restart The GUI / Graphics / Session if it freezes without losing current windows or programs


    Uh oh, so you're working on some super l33t code or other stuff that is super important and Linux Mint's MATE or Cinnamon window manager freezes. This means maybe you can move your mouse but you can't click anything, you can't Alt + Tab to another program but everything appears to be working other than that. The first thing you would do is Ctrl + Alt + F1 (or whatever virtual terminal you want) and get into the Linux bash prompt (the black screen where things really happen :))........
  • Linux ln symlink how to update existing symbolic link


    ln -s --force newfile.jpg existingsymlink.jpg All you do is use the --force flag to force/update the existing one. The above modifies a symlink called "existingsymlink.jpg" and points it to "newfile.jpg" as the source.........
  • How Does Cisco CUCM (Cisco Unified Communication Manager) Work?


    Cisco's CUCM (Cisco Unified Communication Manager) is a system that combines voice, video, data and mobile products into a single unified management suite. At its core, the CUCMis like a "Super PBX" that controls the flow of all communications through an organization even single or multiple site deployments. Cisco's CUCMmakes communication more effective and simple through centralized management and unification of communications resources.........
  • VMWare 6.7 VCSA VSphere ESXi Management SSO Install Guide on Linux using the CLI


    #mount the VCSA DVD mount /dev/sr0 /mnt/cd #alternatively you could mount the iso directly mount -o loop vcsa.iso /your/mount/path #for this purpose we are using the CLI installer on Linux cd /mnt/cd/vcsa-cli-installer/lin64 #no it's not going to be that easy you can't just run vcsa-deploy like that you need to use a template or configured .json file ./vcsa-deploy Usage: vcsa-deploy [-h] [--version] [--supported-deploymen........
  • MySQL Adding New Field to Existing Database Table


    ALTER TABLE existingtable ADD newfieldname VARCHAR(255);........
  • MySQL How To Add New Field Column To Existing Table


    ALTER TABLE thetable ADD newfield VARCHAR(255) It's very simple just specify "the table" and then the newfield type........
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    Centos 5 is not supported running yum will produce an error like this: YumRepo Error: All mirror URLs are not using ftp, http[s] or file. Eg. Invalid release/ removing mirrorlist with no valid mirrors: /var/cache/yum/base/mirrorlist.txt Error: Cannot find a valid baseurl for repo: base Solution - Update this file CentOS-Base.repo # CentOS-Base.repo........
  • Centos 7 Cudaminer Nvidia setup guide


    I am using a GTX 1060 but replace the download for the driver with the correct/current version for your particular card by visiting: http://www.nvidia.com/Download/index.aspx?lang=en-us yum install automake curl openssl-devel libcurl-devel gcc gcc-c++ yum -y install kernel-devel-`uname -r` yum -y install unzip #the........
  • Openshot 2.2 is very unstable always crashing in Linux Mint 18.1!


    Jun 1 15:45:42 videoeditor-desktop org.mate.panel.applet.MintMenuAppletFactory[1882]: project_data:INFO Missing folder chosen by user: Jun 1 15:45:42 videoeditor-desktop org.mate.panel.applet.MintMenuAppletFactory[1882]: project_data:INFO Removed missing file: MAH02949.MP4 Jun 1 15:45:57 videoeditor-desktop org.mate.panel.applet.MintMenuAppletFactory[1882]: ui_util:WARNING Icon theme media-playback-start not found. Will use backup........
  • Migrating from Linux Mint 17.2 mdadm RAID array to a new one (because I upgraded to larger drives).


    1.) Replicate the number of partitions in your new drives. gdisk /dev/sda gdisk /dev/sdb I created 3 partitions of the same same size. partition #1: +1G (/boot) partition #2: +60G (swap) partition #3: rest of it (/) #note if you are using GPT/gdisk you need to create separate a partition at least 1MB in size (in my case I would a 4th partition and mark it type ef02).........
  • remove gpt partition linux


    sudo fdisk /dev/sdh WARNING: GPT (GUID Partition Table) detected on '/dev/sdh'! The util fdisk doesn't support GPT. Use GNU Parted. WARNING: The size of this disk is 8.0 TB (8001563221504 bytes). DOS partition table format can not be used on drives for volumes larger than (2199023255040 bytes) for 512-byte sectors. Use parted(1) and GUID partition table format (GPT). The device presents a l........
  • CPanel SNI error


    Your server does not support SNI, so all of your SSL websites must use the same SSL certificate. An update to the certificate on an existing SSL website will affect all of your SSL websites, and new SSL websites must use the currently installed certificate.........
  • tar do not overwrite files


    It is as simple as using the "-k" option for: -k, --keep-old-files don't replace existing files when extracting --keep-newer-files don't replace existing files that are newer than thei........
  • 2CO/2Checkout how to create recurring payment subscription button dynamically


    It was hard to find this as I find most online payment processors don't just put the basic information in plain view. Remember to set your sid (your seller id). The below can easily be turned into a scripted PHP template to integrate into your own custom or existing payment solution. http://help.2checkout.com/articles/How_to/How-to-Sell-Recurring-Products-with-2Checkout/........
  • Howto Convert Xen Image to KVM


    #count=10000 makes an image of 10000MB make sure your image is at least the same as your existing dd if=/dev/zero of=yourimage.img bs=1M count=10000 # losetup -fv newimage.raw # fdisk -cu /dev/loop0 # kpartx -a /dev/loop0 # dd if= of=/dev/mapper/loop0p1 # e2fsck -f /dev/mapper/loop0p1 # resize2fs /dev/mapper/loop0p1 # a lot of guides tell you to edit /etc/fst........
  • yum Centos 386 and 64 bit conflict resolution


    This can happen when you install RPMForge or other repos with the wrong architecture and here's how you fix it (simply uninstalling won't usually fix it): solution yum clean all yum -y install openvpn Loaded plugins: fastestmirror, presto Loading mirror speeds from cached hostfile * base: mirror.its.sfu.ca * extras: centos.mirror.nexicom.net * rpmforge: mirror.cpsc.ucalgary.ca * up........
  • Directadmin error/** Found 7 pre-existing rpmdb problem(s), 'yum check' output follows: e2fsprogs-devel-1.41.12-3.el6.i686 has missing requires of e2fsprogs-libs = ('0', '1.41.12', '3.el6') e2fsprogs-devel-1.41.12-3.el6.i686 has missing requires of l


    Solution To The Following: yum -y install zlib-devel yum -y install e2fsprogs* *** Cannot find /usr/include/et/com_err.h. (yum install libcom_err-devel) *** Installation didn't pass, halting install. Once requirements are met, run the following to continue the install: cd /usr/local/directadmin/scripts ./install.sh Common pre-install commands: http://help.directadmin.com/it........
  • Setup PXE Boot using Centos and dhcpd, tftp and syslinux


    This is something I often setup for clients because it's very helpful for people in datacenters, this allows custom OS installs on demand, you can customize it more by using kickstart etc.. but here's a base I use before customizing more: This little script below will install everything you need to get booting by PXE Linux. It also assumes you set a local IP (be sure not to overwrite your existing IP) on eth0:0 (note the :0) as 192.168.1.10 and it........
  • 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 IMHOon a production server). You may need to upgrade to PHP5.3 to run Joomla or many other reasons. Your host needs to use PHP 5.2.4 or higher to run this version of Jo........
  • mdadm how to add a device to an array after a failure


    This array is a RAID 1 and in this case 1 of the 2 drives failed (a WD drive and I've found them to be the weakest and most unreliable of any brand and are easily damaged/DOA when shipping them). mdadm --manage /dev/md0 --add /dev/sdb1 The above assumes the array you want to add to is /dev/md0 and the device we are adding is /dev/sdb1 *One thing to remember is to make sure the partition you are adding is the correct size for the array. You can also g........
  • How To Test If Your Hard Drive Is Good/Signs of dying hard drive


    I like dd, although it only reads it, usually a read test of the entire disk will uncover if your hard drive is bad in some parts. This is a good thing to do at least once a month, a lot of times bizarre program behavior, laginess and crashing/unnmounting problems etc.. are due to a failing disc and SMART won't know it or indicate a problem: We must also remember there's never a guarantee, I've found that ever since we moved to larger and more platters per drive with 1TB drives........
  • htaccess modrewrite problem with rewriting url with- dashes solution


    I was getting frustrated with trying to write a simple URL like this: /example-withdash I used the htaccess code like this: Rewriterule ^example-withdash$ / [R=301] I also tried escaping the dash which I thought should have treated it as a literal but that didn't work either: Rewriterule ^example-withdash$ / [R=301] But it wouldn't work, apparently the "-" dash means don't substitute,........
  • Ubuntu 10.04/GRUB2 mdadm won't boot


    Moving to RAID was a pain. What you have to do is the following from an existing install: Install mdadm Create your mdadm RAID 1 array on your spare hard drive. Start it with the missing disk. rsync the entire contents of your current / to the md partition. Here's a good way of doing it: rsync -Pha --exclude=/proc/* --exclude=/sys/* --exclude=/mnt/* /. /mnt/md2........
  • mdadm Linux Software RAID QuickStart Guide


    Create New RAID 1 Array: First setup your partitions (make sure they are exactly the same size) In my example I have sda3 and sdb3 which are 500GB in size. mdadm --create /dev/md2 --level=1 --raid-devices=2 /dev/sda3 /dev/sdb3 mdadm: array /dev/md2 started. Check Status Of The Array *Note I already have other arrays md0 and md1. You can see below that md2 is syn........
  • jailkit for chroot ssh account security tutorial and fix for error


    This was done on Centos butI think it's easier on Debian machines, the paths that it is set to use are tailored towards Debian, so there is some fiddling that needs to be done on Centos. This is for chrooting ssh, but jailkit has other uses than just SSH jails but I won't cover them in this writeup. 1. Install jailkit yum install jailkit 2. Setup Jail Home mkdir /home/jail chown root:root /home/ja........
  • FUSE/Curlftpfs mount ftp account as drive partition in Linux


    This is a great way to use your ftp server space, for example on your web hosting account (althoughI believe many hosts don't allow storage like this), but if you have a VPS/Dedicated Server etc.., this would be perfect. Imagine how easy it is to work with an ftp account that you can just mount as a normal partition or directory in Linux, it would be great for backups etc.. Name curlftpfs - mount a ftp host as a local directory Synopsis........
  • mdadm can you downgrade the superblock?


    Why would you want to downgrade the superblock? Old mdadm verisons like mdadm 2.5.6 only use the 0.90 superblock/metadata and new versions use 1,1.0,1.1 and 1.2 superblocks by default. There are some annoying caveats with this, first of all the new superblocks (later than 0.90) CANNOT be read by GRUB, so you won't even be able to install GRUB. Even worse, old versions of mdadm CANNOT automatically detect arrays even if they were created with a new version of mdadm with th........
  • Convert HDD/Hard Drive Partition(s) into non-RAID into RAID 1 using existing data without data loss and without reformatting.


    Before we start I take no responsibility for this, you should have a backup and if you make a mistake during this process you could wipe out all of your data. So backup somewhere else before starting this as a precaution, or make sure it's data you could afford to lose. The RAID 1 Setup (Hardware Wise) I've already setup my 2 x 1TB (Seagate) drives with identical partitions, make sure your new hard drive (the empty one) is setup like your curr........
  • Nice General Linux RAID 1 Guide


    Nice General Linux RAID 1 GuideFull examples/tutorials that should work for any Linux system using GRUB or LILO as the boot loader. This is the only tutorial I've seen that clearly shows how you can convert an existing non-RAID system to software RAID1 remotely, without ever having to be at the computer. This is important for people who co-locate or rent dedicated servers that they may not have physical access to in a timely manner. https://alioth.debia........
  • Heredoc warnings


    Heredoc warningsExample $somevariable = ........
  • Centos 4.3 x64 & VMWare Server Beta


    Centos 4.3 x64 & VMWare Server Beta[code:1:6d0b2c8c2f] The correct version of one or more libraries needed to run VMware Server may be missing. This is the output of ldd /usr/bin/vmware: linux-gate.so.1 => (0xffffe000) libm.so.6 => /lib/tls/libm.so.6 (0xf7fbd000) libdl.so.2 => /lib/libdl.so.2 (0xf7fb9000) libpthread.so.0 => /lib/tls/libpthread.so.0 (0xf7fa7000) libX11.so.6 => not f........
  • How to compile in Windows/DOS


    How to compile in Windows/DOSMingW is a free compiler project so start here: http://www.mingw.org/download.shtml#hdr2 I downloaded the core GCC compiler: http://prdownloads.sf.net/mingw/gcc-core-3.4.2-20040916-1.tar.gz?download But it's missing even the standard C runtime libraries like "stdio.h"! You may also need to add environment variables from the DOS command line. Here is a simpl........
  • The New Chips on the Block


    The New Chips on the BlockThe New Chips on the Block By Bruce Gain Story location: http://www.wired.com/news/infostructure/0,1377,67795,00.html 02:00 AM Jun. 13, 2005 PT We have embarked upon a new era in x86 PC computing -- so say chip giants AMD and Intel following their launches of dual-core PC processors. So how will dual-core processing change your PC computing experience? Our FAQ should help you decide whether or when you sho........
  • Intruder detection device uses behavioural analysis


    Intruder detection device uses behavioural analysisIntruder detection device uses behavioural analysis by Antony Savvas Monday 13 June 2005 Symantec is introducing a new intrusion detection product that uses behavioural analysis to block potential attacks on enterprise networks. The new Critical System Protection 4.5 system uses technology that Symantec acquired through last year’s purchase of Platform Logic. It is designed to protect deskt........
  • Asterisk Agent Login Problem


    Asterisk Agent Login ProblemUsing the AgentCallbackLogin function I couldn't login I knew I had my agents setup properly in agents.conf so why couldn't I login? The reason is because agents.conf was missing the [b:994d7a34af][agents][/b:994d7a34af] context! I just added [agents] above the existing agent declarations and then I was able to login as expected. It took a lot of figuring out and reading though!........
  • MySQL Server 3.23 won't start after switching from 4.1


    MySQL Server 3.23 won't start after switching from 4.1I was using a 4.1 alpha version of mysql-server and some how version 3.23 of the client and 4.1 of the client were also both installed! So I forced uninstalled everything because after trying and trying even though MySQL server was using the short 16byte password authentication I got some other errors. After trying with the ports and having it fail because I had existing database data I force installe........
  • Changing field names


    Changing field names[quote:91ea6831b6]ALTER TABLE [u:91ea6831b6]table_name[/u:91ea6831b6] CHANGE [i:91ea6831b6]existing_field_name[/i:91ea6831b6] [b:91ea6831b6]new_field_name[/b:91ea6831b6] INT(11);[/quote:91ea6831b6]........
  • Create Table with structure of another existing table


    Create Table with structure of another existing tableOk, this has many valid uses such as if you need to create backups or the ability to undo changes, you would want to create new tables with the same structure as another. Here is how you do it. [i:7ed9581493] Also remember Indexes such as PRIMARY KEYS [b:7ed9581493]will not be preserved[/b:7ed9581493] so you will have to readd them manually.[/i:7ed9581493] [code:1:7ed9581493]CREATE TABLE NewName AS SEL........
  • Clustered/Distributed Network Filesystems, Which Ones live up to the hype?


    I've tried to find a good sensible solution to cluster with and each technology has it's pros and cons and there is no perfect solution and I've found a lot of "exaggerations" in the applications, benefits and performance of these different filesystems. DRBD I first started off with DRBD and Ihave to say it does live up to the hype, is quite reliable (although it can be annoying to match up the kernel module and user applications since they must match and whe........
  • Timezone Change/Updated for Linux/Unix Debian/Fedora/Ubuntu/Centos Change Update Time zone


    This way should work on all Linux machines, at least RHEL/Debian (Ubuntu) based distros but most likely all and also should work on many Unix style machines I believe. Many OS's have tools to update the timezone, but most of them (even if command line) require several bloated packages and even Xorg/KDE based packages etc.. Your time zone info file is actually in /etc/localtime if you open this file in vi/vim/pico you'll see it's gibberish (binary code or another encodin........
  • Apple iPhone 3GS and predecessors are leading a revolution


    As much of a computer nerd as Iam, I'm usually a late adopter to technology for a few reasons. Ifeel most new hyped technologies and electronics are mainly fads, and I'm also cheap. Adopting later means you avoid the bugs, kinks and most importantly pay the lowest price, that's me being cheap again :) I never read much about the iPhone but Isaw all the hype around it and until recently I wasn't a big fan of anything Apple until a few years ago I realize........
  • SSH Slow Login even with SSHD UseDNS no parameter


    Icouldn't understand why on one system it took a few minutes to get the SSHlogin prompt when connecting to other systems. The other systems all had the UseDNS parameter set to no, which almost always resolves the login prompt delay. The reason is Ubuntu and perhaps Debian and other distributions /etc/nsswitch.conf file Edit yours to have the "hosts" line like so (notice that files and dns are the primary resolution choice........
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