Docker Swarm vs Kubernetes Comparison Guide

A lot of companies are unsure which solution to choose and many may not be aware of Docker Swarm as an alternative to Kubernetes. One thing that many Sysadmins find is that Docker Swarm is simply easier, quicker to setup and maintain by far than Kubernetes.........

Can't exec "aclocal": No such file or directory at /usr/share/autoconf/Autom4te/FileUtils.pm line 326. autoreconf: failed to run aclocal: No such file or directory solution

autoreconf: Entering directory `.' autoreconf: configure.ac: not using Gettext autoreconf: running: aclocal --output=aclocal.m4t Can't exec "aclocal": No such file or directory at /usr/share/autoconf/Autom4te/FileUtils.pm line 326. autoreconf: failed to run aclocal: No such file or directory make: *** [/software/pixman/configure] Error 1 Just install automake: yum install automake........

How To Upgrade Debian 8,9,10 to Debian 12 Bookworm

Step 1.) Upgrade to Debian 11 first The process to go to Debian 12 is not as smooth as 11, when trying to upgrade from Debian 10. In fact, it doesn't work directly, so you'll first need to follow this guide to update to Debian 11, reboot and come back here if successful. Step 2.) Update sources.list Update your /etc/apt/sources.list like this: deb http://........

How To Setup Python3 in Ubuntu Docker Image for AI Deep Learning

The issue is that Docker images are stripped down, so many tools and even python3 is missing, so you'll have to build or update the actual image yourself. I assume you have started an image with something like this and that you have the Nvidia Toolkit installed (assuming you are using GPUs). If you're not using nvidia just remove --runtime=nvidia --gpus all. docker run -it --runtime=nvidia --gpus all ubuntu bash These works for most images li........

ecryptfs how to manually encrypt your existing home directory or other directory

Just in case, it is reocmmended to backup the original contents of the directory (especially your home dir) before proceeding. Setup ecryptfs Run this command: ecryptfs-setup-private It will ask you for your login password, this is so that when you login, everything is automatically decrypted by using a passphrase that is wrapped with your login. You can hit enter and leave things blank for an autogenerated passphrase (for mounting) or you can en........

vi cannot copy and paste automatic visual mode solution

See below in the screenshot that copy is disabled by visual mode which enables automatically: Fix it by setting this .vimrc option: echo "set mouse-=a" >> ~/.vimrc........

How to install and configure haproxy on Linux Ubuntu Debian

haproxy is one of the best known and widely used Open Source load balancers out there and a strong competitor to nginx. haproxy is used by many large sites per Wikipedia: HAProxy is used by a number of high-profile websites including GoDaddy, GitHub,........

vagrant install on Debian Mint Ubuntu Linux RHEL Quick Setup Guide Tutorial

1 - Install Vagrant apt install vagrant Make sure you have a supported Virtualization tool like Virtualbox or VMWare, Hyper-V etc.. It automatically detects and uses what you have. Virtualbox has a lot of support here with tons of images. 2 - Init Vagrant We'll init to have a Debian 10 box by default to show how quick and easy it is. vagrant init generic/debian10........

Linux grub not using UUID for the root device instead it uses /dev/sda1 or other device name solution

You can read lots of posts about this issue but there is not much information about why this is the case or how grub determines the root= device name. Some even suggest modifying grub.cfg manually which is a disaster as the next kernel update will cause grub to revert back to the device name. For most people this won't be an issue but those using template system, automated deployments and working in embedded may run into this issue with custom embedded and created minimal kernel........

Debian Ubuntu apt install stop daemon questions/accept the default action without prompting

This can be a real pain when automating things and you do an apt install and some packages ask a lot of questions. Make sure you set this variable when running: DEBIAN_FRONTEND=noninteractive Remember as well that if chrooting you will want to run like this: DEBIAN_FRONTEND=noninteractive apt install -y yourpackagename ........

Cisco UC CME How To Enable Licensed Features

Router#show license Index 1 Feature: ipbasek9 Period left: Life time License Type: Permanent License State: Active, In Use License Count: Non-Counted Lic........

Ubuntu Mint Debian Howto Execute Command / Script / Program Upon Wakeup From Sleep

Sometimes manual intervention on various Linux system's, including Debian, is required to fix things after waking up from sleep. One persistent issue is the sound system / pulseaudio needing to be reset and not working until you do that after waking up. It's not clear if it's an OS issue itself or the sound driver, but this will fix things. Where do we put scripts or commands that need to be used upon wakeup automatically? /lib/systemd/syst........

GlusterFS HowTo Tutorial For Distributed Storage in Docker, Kubernetes, LXC, KVM, Proxmox

This can be used on almost anything, since Gluster is a userspace tool, based on FUSE. This means that all Gluster appears as to any application is just a directory. Applications don't need specific support for Gluster, so long as you can tell the application to use a certain directory for storage. One application can be for redundant and scaled storage, including for within Docker and Kubernetes, LXC, Proxmox, OpenStack, etc or just your image/web/video files or even da........

(firefox:9562): LIBDBUSMENU-GLIB-WARNING **: Unable to get session bus: Failed to execute child process "dbus-launch" (No such file or directory) Solution

(firefox:9562): LIBDBUSMENU-GLIB-WARNING **: Unable to get session bus: Failed to execute child process "dbus-launch" (No such file or directory) ExceptionHandler::GenerateDump cloned child 9743 ExceptionHandler::WaitForContinueSignal waiting for continue signal... ExceptionHandler::SendContinueSignalToChild sent continue signal to child [Parent 9562, Gecko_IOThread] WARNING: pipe error (40): Connection reset by peer: file /build/firefox-EymEXX/fire........

Docker Tutorial HowTo Install Docker, Use and Create Docker Container Images Clustering Swarm Mode Monitoring Service Hosting Provider

The Best Docker Tutorial for Beginners We quickly explain the basic Docker concepts and show you how to do the most common tasks from starting your first container, to making custom images, a Docker Swarm Cluster Tutorial, docker compose and Docker buildfiles.........

How To Startup and Open Remote/Local Folder/Directory in Ubuntu Linux Mint automatically upon login

Just click on the Start Menu and go to "Startup Applications" Then click on the "Add"Button Now enter the command we need to open the folder/directory automatically using the filemanager For remote SSH host (you need pub key auth for it to open without a pa........

ssh-keygen id_rsa private key howto remove the passphrase so no password is required and no encryption is used

The key is that you need to know the passphrase to do it, if you don't know the password for the key then you can't remove the key since it cannot be decrypted. ssh-keygen is the easiest method and openssl can be used to manually remove the key and output it to a new file, which you can then copy back over top of the encrypted file. After that your public key authentication will work without any password prompt because it is no longer encrypted. Make sure you understand........

Wazuh / OSSEC Install and Configuration Howto Tutorial Guide for Monitoring Agents SIEM

How To Install Wazuh Server / Quickest Installation Wazuh (forked from the well known OSSEC project) is a full SIEM (Security Information Event Management) that works extremely well with the platforms it natively supports as an "Agent", which allows you to do scans of everything such as all processes running, CVE vulnerability check, incident reporting etc... Prerequisites: A lot of issues with Wazuh seem to be caused by i........

How to allow SSH root user access in Linux/Debian/Mint/RHEL/Ubuntu/CentOS

A lot of newer installs will automatically prohibit the root user from logging in directly, for security reasons or they will only allow key based access. If you know what you are doing/don't care about security or have an incredibly secure password for testing, then you can enable it. Edit this file: /etc/ssh/sshd_config Find the following line: PermitRootLogin Set it like this: PermitRootLogin yes Now rest........

Ansible Tutorial - Playbook How To Install From Scratch and Deploy LAMP + Wordpress on Remote Server

1. Let's work from an environment where we can install Ansible on. If you are using an older version of Linux based on Mint 18 or Ubuntu 16, you may want to get the PPA and get the latest version of Ansible that way: sudo apt install gpg sudo add-apt-repository ppa:ansible/ansible sudo apt update........

Linux Grub not booting the intended kernel solution in Debian, Mint, Ubuntu how to specify which kernel to boot by default

Traditionally kernels were numbered starting from 0 but by default the "new style" of grub boot loading considers each subkernel item to be different so if you have 3 entries for 4.40-148 rather than counting for 1. To get the expected behavior let's show this example and how we can boot it We do a grep on menuentry in /boot/grub/grub.cfg to see all of the bootable kernels rather than scrolling through loads of extra entries we don't care about (thou........

kdenlive full reset how to erase all config files

kdenlive is VERY finicky especially if using an older or newer version it can cause crashes, menus not to work, features not to work, things not to work properly. A good example is that Icould NOT get automask to work, there would be no box to control it until I did this full reset. One caution is that your backup project files will be erased when doing this: How to Reset kdenlive entirely rm ~/.config/kdenlive-layoutsrc rm........

Linux How To Stop Missing Drive from Halting Boot Process in fstab

When you automount a drive in /etc/fstab even if it's not important like an external drive that you only use sometimes and is not required for booting, it will prevent a successfuly boot. If you disable quiet mode for booting you will see something like below "A start job is running for dev-disk ...." How do we fix an fstab entry from preventi........

How To Password Reset, Recover, Bypass, Remove and Unlock on Windows 10,8,7,Vista,XP,NT,2000,2003,2008,2012,2016,2019 Administrative Login Programs

If you've come here, don't be embarraassed, working in IT, this is the MOST common computer problem that almost everyone will encounter. The reason why I'm doing this post is because I've seen an increase from colleagues and admins having this problem and many times it's not even your fault. A common scenario is that someone acquires a new or used computer which they weren't given the password for. Fortunately Ihave a detailed list of all the options whether free or pa........

How To Get Started on Ubuntu with gpt-2 OpenAI Text Prediction

apt install software-properties-common add-apt-repository ppa:deadsnakes/ppa apt update apt install python3-pip apt install python3.7 curl gnupg python3.7-dev git ln -s /usr/bin/python3.7 /usr/bin/python3 pip3 install numpy keras_preprocessing curl https://bazel.build/bazel-release.pub.gpg | sudo apt-key add - echo "deb [arch=amd64] http://storage.googleapis.com/bazel-apt stable jdk1.8" | sudo tee /etc/apt/sources.list.d/bazel........

How To Install python 3.4 3.5 and up on Linux with wine - Working Solution

This is sure simple if you follow the guide but it took a lot of hacking around to make this work on Debian/Ubuntu! Now before you ask why bother running wine and python, the reason is because Python executables are NOT cross-platform. If you run pyinstaller in Linux, that binary will only run on Linux and the same if you do it in Windows. So it is preferable if you have a single environment that you can create Linux and Windows binaries from rather than running 2 separate........

CentOS 8 how to convert to a bootable mdadm RAID software array

The cool thing here is that we only need 1 drive to make a RAID 10 or RAID 1 array, we just tell the Linux mdadm utility that the other drive is "missing" and we can then add our original drive to the array after booting into our new RAID array. Step#1 Install tools we need yum -y install mdadm rsync Step #2 Create your partitions on the drive that will be our RAID array Here I assume it is /dev........

MySQL Bash Query to pipe input directly without using heredoc trick

Most of us know the heredoc method but what if you need a basic query done repeatedly and manually while working from bash? It is a pain to manually type mysql and login each time. With this command below you can semi-automate those queries: echo "use somedb; select * from auctions" | mysql -u root --password="yourpassword" Just modify the above to suit your needs and you can add more queries by adding a sem........

Linux delete unused tap devices automatically

This will find all tap devices and try deleting all of them. Of course don't run this if there is a chance an unused tap device is necessary and would not be created by the script ro application using it. for tap in `ifconfig -a|grep tap[0-255]|awk '{print $1}'`; do tunctl -d $tap done........

qemu-kvm qemu-system Image format was not specified for '/mnt/space/cucm12.img' and probing guessed raw. Automatically detecting the format is dangerous for raw images, write operations on block 0 will be restricted. Specify the 'ra

WARNING: Image format was not specified for '/mnt/space/cucm12.img' and probing guessed raw. Automatically detecting the format is dangerous for raw images, write operations on block 0 will be restricted. Specify the 'raw' format explicitly to remove the restrictions. #you should manually specify the format q........

SSH proxy/command in the background or from cron script

If you have an SSHproxy that you need to run automatically from cron you will need it in the background to work. ssh -N -D 22000 user@domain.com Basically the -N let's it continue running in the background.........

proxmox vm networking breaks when you restart your network on the hostnode

Idid a systemctl restart networking and it broke Proxmox VM connectivity! #proxmox is the problem after restarting the network the tap devices go to disabled state [2230884.919905] vmbr0: port 7(tap118i0) entered disabled state [2230884.948864] vmbr0: port 8(tap122i0) entered disabled state [2230884.972748] vmbr0: port 6(tap119i0) entered disabled state [2230885.004745] vmbr0: port 5(tap117i0) entered disabled state [2230885.03673........

Thunderbird How To Disable An Email Account

Navigate to Tools -> Account Settings -> Server Settings Uncheck the following: "Check for new messages on startup" "Check for new messages every NN minutes" "Automatically download new messages". Source: http://forums.mozillazine.org/viewtopic.php?t=635510........

Debian Linux Mint Ubuntu iptables save and restore settings automatically onboot and reboot

First you need the "iptables-persistent" package. This gives you an init script that loads your settings from /etc/iptables/rules.v4 and rules.v6 When you install it, it wll save your default setings in /etc/iptables. sudo apt-get install iptables-persistent Remember that the rules are stored here: For IPV4: /etc/iptables/rules.v4 For IPV6: /etc/iptables/r........

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........

linux mint image convert menu option missing solution

Ialready have the caja-image-converter option installed but it shows nothing. Weirdly enough if you install nemo and nautilus converter it does show and work inside caja: The solution is to install *-image-converter sudo apt-get install *-image-converter Reading package lists... Done Building dependency tree Reading state information... Done Note, selecting '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........

Linux Mint Ubuntu Debian How To Disable Webcam Automatically Onboot To Prevent Spying and Privacy Violations

It is well known hackers, the NSA, CIA and other groups have created malware to secretly turn on your webcam and microphone on your phone, tv etc.. But fortunately on our computers and laptops we have some options. Most webcams use the "uvcvideo" kernel module / driver. You can disable this in two ways on boot. I recommend both just as a failsafe. Disable it on rc.local once your system boots automatically Add the followi........

How To Install Windows Server 7 8 10 12 2008 2012 2014 2016 Servers Desktops using Linux tftp, dhcpd and samba

It has been a big pain for a long-time to install Windows from a Linux environment. I used to run a windows install server and it never worked right for some reason (the install would fail on most servers). Before getting start be sure to setup your samba share so once you boot into WinPE you can mount the install for whatever Windows you want /etc/samba/smb.conf [smbwinstall] path = /tftpboot/images/winstall guest ok = yes........

bash find line and replace howto

First find the line number: awk '/what you are searching for/{ print NR; exit }' input-file 86 Now use sed to replace it: sed -i 86s/.*/"your replacement text"/ $file Here is a full sample script to automate it: file=some/f........

How to find and mount mdadm arrays automatically

A great way if you have a bunch of drives and mdadm connected and are looking for backups/archives and don't know what is where! for md in `cat /proc/mdstat|grep md[0-99]|awk '{print $1}'`; do mkdir /mnt/$md; mount /dev/$md /mnt/$md; done........

linux cp and mv will not overwrite due to alias!

This through me for a loop when I would do a cp -rf or mv -f nothing would get overwritten even if piping y or yes to the command. Type alias and you'll see why: alias cp='cp -i' alias l.='ls -d .* --color=auto' alias ll='ls -l --color=auto' alias ls='ls --color=auto' alias mv='mv -i' alias rm='rm -i' The -i is a safeguard against messing things up but however does mess things up worse when you know what........

FreeBSD/OpenBSD OpenVPN Client error "Cannot allocate TUN/TAP dev dynamically"

I have never had this error on Linux and this is running FreeBSD as root: Wed Aug 9 04:29:34 2017 us=329050 Cannot allocate TUN/TAP dev dynamically Wed Aug 9 04:29:34 2017 us=329832 Exiting due to fatal error The Solution you need a kernel module that is for some reason not automatically loaded like Linux: kldload if_tap........

Cannot allocate TUN/TAP dev dynamically - FreeBSD/OpenBSD OpenVPN Client error Solution

I have never had this error on Linux and this is running FreeBSD as root: Wed Aug 9 04:29:34 2017 us=329050 Cannot allocate TUN/TAP dev dynamically Wed Aug 9 04:29:34 2017 us=329832 Exiting due to fatal error The Solution You need a kernel module that is for some reason not automatically loaded like Linux: kldload if_tap........

Wine uninstalled broken on Linux Mint

Solution: Aptitude is very smart and fixed the issues it was because of nvidia cuda and opencl and nothing else suggested or hinted this using apt sudo aptitude install wine The following NEW packages will be installed: ocl-icd-libopencl1{ab} ocl-icd-libopencl1:i386{ab} wine wine1.6 wine1.6-amd64{a} wine1.6-i386:i386{a} The following packages will be REMOVED:........

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........

Avocent DSR8020 KVM/IP - Network Connect Error - Solution

This error is commonly due to Java security or TLS settings but there is a second issue with forwarded ports that also causes it. 1. Java Security/TLS Settings issue: This article has the solution to change them all in Linux automatically 2. Port Forwarding Issue if your Avocent DSR is behind NAT/private IP........

How to verify SSL SHA-1 Certificate Fingerprnit Signature of your mail/web server to avoid hijacking/man-in-the-middle attacks

This is especially helpful if you run your own servers. If you are presented with an error message or warning that the signature has changed or does not match the IP/domain you are connecting to you always want to verify manually. So your e-mail/web client will show you an SHA-1 fingerprint like this: "Could not verify this certificate because the issuer is unkown" or other reasons such as a mismatch in IP/domain. It will also show you........

Linux how to reformat html file code solution

The solution is simply "tidy"/Tidy-HTML. It will take your poorly formatted HTML code (and I mean files that span just a few lines that are unreadable) and fix it up. Note the command below does everything in place. *Make sure you take a backup of all .html files* It also seems to break html5 code/templates so beware. tidy -im yourfile.html An automated way in bash:........

ImageMagick how to trim white space automatically in Linux

convert -trim yourimage.png That's all there is to it, very simple, clean and quick!........

mdadm change wrong device name md127 fix and solution in Linux

md127 issue, it should be /dev/md3 per mdadm.conf Any time something is mounted as md127 it almost always means there is no entry for this mdadm array in the mdadm.conf in initramfs (which is separate from your actual /etc/mdadm.conf). cat /etc/mdadm.conf ARRAY /dev/md3 metadata=1.2 UUID=b6722845:381cc94e:7a2c5b5f:8e3b7c4f The reason for this is something strange, most Linux OS's bizarrely always keep their own copy of /etc/mdadm.con........

Linux Mint 17 How to Enable File Sharing Option in File Manager

I still cannot understand how this would not be enabled by default and I struggled to find the reason why with manually installing samba etc.. wondering why the option for sharing was not in the menu. On Linux Mint "MATE" the package is called "caja-share" and on Cinnamon it is called "nemo-share" so edit the below command as necessary: *Also note that the "samba" package is necessary as it is not inst........

openvpn 2.3.10-1.el6 issues auth-env does not work correctly for auth-user-pass-verify

openvpn 2.3.10-1.el6 issues in the .conf auth-user-pass-verify "passwordcheck $username $password $untrusted_ip" via-env auth-env does not work correctly in OpenVPN 2.3: Sat Apr 23 02:30:22 2016 - $username - $untrusted_ip - login failure But OpenVPN 2.2 does work as expected. It could be that the specified script automatically receive........

Centos 6 how to guide convert LVM non-RAID into mdadm 1/10 RAID array live without reinstalling

Here is the scenario you or a client have a remote machine that was installed as a standard/default minimal Centos 6.x machine on a single disk with LVM for whatever reason. Often many people do not know how to install it to a RAID array so it is common to have this problem and why reinstall if you don't need to? In some cases on a remote system you can't easily reinstall without physical or KVM access. So in this case you add a second physical or disk or already ha........

Installing zoneminder on Ubuntu/Debian Linux Howto

sudo apt-get install zoneminder [sudo] password for one: Reading package lists... Done Building dependency tree Reading state information... Done The following packages were automatically installed and are no longer required: libuser-perl python-evince kdebase-apps kwrite unixodbc libgnomeprint2.2-data python-soappy vgabios python-metacity hddtemp python-mediaprof........

HP Procurve Switch 2824 CLI Telnet Experience , Guide and Tutorial

------------------------------------- ProCurve J4903A Switch 2824 Software revision I.10.77 Copyright (C) 1991-2009 Hewlett-Packard Co. All Rights Reserved. RESTRICTED RIGHTS LEGEND Use, duplication, or disclosure by the Government is subject to restrictions........

Cannot mount iPhone or iPad in Linux

Unable to mount iPad 4 Unhandled Lockdown error (-4) This is because you need the libimobiledevice-utils package installed and a newer version of it. My older Ubuntu 10.10 uses a version that does not have "idevicepair" which seems to work perfectly and automatically with newer versions of the library. Basically if you install the above library it should be plug and play and if your imobiledevice-utils doesn't have 'idevice........

PayPal subscriptions automatically cancelling after creation of profile

There is a weird quirk with how this works, but there is a variable called "src" that defaults to 0 or disabled if not specified as 1. The default 0 means not to recur billing on a subscription. It's too bad it's not more obvious anywhere nor is there an explanation or warning during payment or after to both the seller and buyer. Here's a proper subscription code example that does recur and does not cancel........

CPanel Link to all of the command line options

CPanel says you can access 98% of the functions through CLI which experienced Unix/Linux admins prefer for simplicity and for scripting. I've never found CPanel easy to use from the admin panel, it seems everything is hard to find and a simple task becomes a series of hunts. So for people like me here's the list: http://cpanel.net/system-administrators/command-line-scrip........

LibreOffice Recovery Automatically Saved Documents

Browse to this directory: ~/.config/libreoffice/3/user/backup/........

PHP How To Create and Assign Variables from POST/Submit FORM

foreach ($_POST as $key => $value) { if ( $key != submit ) { $values.="$key=$value<........

eth0 changed to eth1 or eth2 and the solution to fix it

If you move your hard drive(s) around to other computers/servers, you'll find that your eth0 keeps getting higher, the first time it will become eth1 and then eth2 etc and even higher if your server has dual or quad NICs. The reason is that udevd basically assigns eth0 tot he first NIC it finds and remembers it, if it encounters a NIC with a differentMAC, it assigns it one higher (eg. eth1). See the example below, I have eth2 now so how doI fix it?........

Delete arp entry from Linux Howto

arp -a syst (192.168.1.122) at 21:96:43:3a:62:a2 [ether] on eth0 arp -d 192.168.1.122 If you get an error do: arp -d 192.168.1.122 -i eth0 Sometimes the arp cache just won't clear either, some say it should automatically but there are cases where the above doesn't work. I believe it may be that some network applications are keeping the entry alive but this is just a guess.........

Thunderbird How-To Copy/Backup/Restore Accounts and Settings to Another Computer

The best way is to use rsync, I've set it up so it doesn't copy unnecessary files, or at least ones I'm sure aren't needed. Here is the rsync command Iused (adapt to your specific Thunderbird profile location): rsync -hazv user@remotehost.com:/home/user/.thunderbird/sbrer.default/* /home/user/.thunderbird/4nyb0.default/ --exclude=global* --exclude=Cache --exclude=ImapMail --exclude=Mail This is a great way to get your e-mail accounts going on a new c........

KVM/QEMU Base/Template Images and the power they provide

qemu-img create -b centos.5-8.x86.20120308.qcow2 -f qcow2 ../kvmguests/25000-centos5.8x86.qcow2 Formatting '../kvmguests/25000-centos5.8x86.qcow2', fmt=qcow2, backing_file=centos.5-8.x86.20120308.qcow2, size=10485760 kB -b the source/base image -f format is qcow2 and the location of the destination image What is so special about this? It's even quicker than creating a template with OpenVZ but this is an actual OS. It saves time a........

Linux/Centos how to block SSH bruteforce/dictionary attacks automatically with denyhosts

A lot of people become nervous (and understandably so) when checking their auth or security logs, in Centos /var/log/secure and see dozens, hundreds of even thousands of attempted logins to various services, especially SSH. Of course you could manually block these people/IPs but no one has time to read the logs like that, what if some program or script could do it for you? This is what denyhosts does for you, it checks the logs and based on a certain number of failed SSH attem........

Debian UUID not working

Neither the blkid or the UUID internal to mdadm work to automount for some reason in Debian partprobe doesn't work but was a good suggestion from: http://pato.dudits.net/2008/11/03/special-device-uuidxxxxxxxxxxxxxxxx-does-not-exist-especially-with-lvm mount: special device /dev/disk/by-uuid/431b9b96-29e8f298-e89bd504-7065bddd does not exist mdadm -D /dev/md_d12 mdadm: metadata format 00.90 unknown, ignored. /dev/md_d12: &nb........

Skype Linux/Ubuntu Sound Echo/Distortion Poor Quality Problem Fix Solution

This was very annoying but has a simple fix, I had an echo and the voice quality was absolutely horrible (it sounded like tin cans under water) if that helps describe it. It was extremely distorted. The simple Skype sound quality solution Go to "Options" -> "Sound Devices" Disable the "Allow Skype to automatically set my mixer levels" After doing this the sound qua........

Ubuntu 10 Nvidia Drivers Not Updated After Kernel Update Solution/How-To Manually Rebuild nvidia kernel modules for Ubuntu

I dread updating the kernel and rebooting to find the Ubuntu graphics aren't working and you have to manually intervene. This is usually because Ubuntu for whatever reason didn't update the drivers you need (eg. the manually compiled Nvidia Kernel driver that MUST be recompiled for each and every kernel update unfortunately). The most common reason may be that "linux-source" hasn't been installed automatically on my system. I tried to manually reinstall the........

wget download all files on page/directory automatically recursively

Have you ever found a website/page that has several or perhaps dozens, hundreds or thousands of files that you need downloaded but don't have the time to manually do it? wget's recursive function called with -r does that, but also with some quirks to be warned about. If you're doing it from a standard web based directory structure, you will notice there is still a link to .. and wget will follow that. Eg. let's say you have files in http://serverip/documen........

Yahoo Mail (email) DNS Server Out Of Date Problems

I don't expect this to be solved soon but some of Yahoo's DNS servers are out of whack. I changed the IPs of some nameservers of some domains and now most Yahoo users can't e-mail to those domains! As you can see below by the "No MX or A records for mychangedomain.com", now Yahoo's DNS/mailserver DNS cache is wrong. You would think they would at least have cached the old incorrect records, but instead for some reason their DNS cache has no entry and doesn't seem........

Amarok won't play songs, keeps skipping to the next

Amarok won't play songs, keeps skipping to the next Some say install install phonon-backend-xine but it was already installed automatically, obviously that's not the problem or solution. Settings -> Configure Amarok Playback: Configure Phonon Audio Output: Music It should show your different audio interfaces, choose Pulse Audio and move it to the top of the list, do the Apply, OK and manually quit Amarok (remember to close it from the tra........

tar how to include hidden files such as .htaccess when it doesn't automatically

tar include hidden files such as .htaccess just add . to the path eg. tar -czvf tarfile.tar.gz /home/directory/.........

mysqldump does not include CREATE DATABASE statement

mysqldump does not include CREATE DATABASE statement you need the --databases option "--databases" is misleading, it implies in the documentation that this is a list of databases to be dumped, it should be clear that uses this command in conjuction with dumping a single database also adds CREATE DATABASE and is the only way to get the database to automatically create itself.........

Installing Webmin & Enabling SSL

Webmin Setup Centos 5: wget http://downloads.sourceforge.net/project/webadmin/webmin/1.530/webmin-1.530-1.noarch.rpm?r=http%3A%2F%2Fwww.webmin.com%2Fstandard.html&ts=1294339690&use_mirror=surfnet [1] 24229 [2] 24230 [root@host ~]# --2011-01-06 21:48:20-- http://downloads.sourceforge.net/project/webadmin/webmin/1.530/webmin-1.530-1.noarch.rpm?r=http%3A%2F%2Fwww.webmin.com%2Fstandard.html Resolving downloads.sourceforge.net... 216.34.181.........

rsync preserve attributes, permissions/ownership and times without being root non-root user

One of the purposes of rsync is to backup whole filesystems and archive them but how can you do that properly and restore things to normal if all permissions and ownerships are not preserved from your root filesystem? It's not desirable to have everything running as root, especially not just for an rsync. The Easy rsync preserve permission solution for non-root users sudo is the answer and all you have to do is edit /etc/sudoers At the end o........

Ubuntu/Debian DRBD 8.0 Setup Guide

I've only used it on Centos, soI thought I'd make a quick Debian guide: Install the DRBD Package apt-get install drbd8-utils Reading package lists... Done Building dependency tree Reading state information... Done The following packages were automatically installed and are no longer required: libswfdec-0.8-0 Use 'apt-get autoremove' to remove them. The following........

yum error with some versions of Centos Refusing to automatically import keys when running unattended. Use "-y" to override.

Refusing to automatically import keys when running unattended. Use "-y" to override. When using echo y|yum install gcc Fix with rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY*........

Wine stopped working/won't work Solution

After an upgrade wine wouldn't open anything, not even the pre-installed notepad. There are no wine logs and nothing is mentioned in any standard log file about why. I finally decided to run wine from the shell and see what's going on: wine client error:0: version mismatch 398/402. Your wineserver binary was not upgraded correctly, or you have an older one somewhere in your PATH. Or maybe the wrong wineserver is still running?........

sed script to automatically update IPs in named/BIND and httpd/Apache

Always make a backup of the original file before trying this, I find this kind of thing when updating IPs etc.. to use a script. Where the old IP is "192.168.5.8" and the new IP is "10.10.5.8" sed -i s/192.168.5.8/10.10.5.8/g testdomain.org.db The -i with sed means "inline" meaning we edit the file directly, but without the -i we could just use >and output the results to another file or do whatever else we wanted.........

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........

How To Set DHCP/Static IP Address in Centos/RHEL/Fedora & Debian/Ubuntu/Kubuntu/MEPIS Set DHCP/Static IP Address

Basically the two main types of distros are Debian and RHEL/Centos based. I'm just going to give a quick overview of how the configuration of IP interfaces works in Debian/Centos based distros. *Just one thing to remember, when setting IPs statically you have to manually specify a DNS server in /etc/resolv.conf (since DHCP is what normally does it automatically) Debian/Ubuntu/Kubuntu/MEPIS The IP (DHCP &........

SSH Automatic/Passwordless Logon - Setup Public Key Encryption In Single Command

This is a very simple solution, but most guides out there make you login twice (once to scp the key) and once to put the key in authorized_keys. There's no need for that. If you don't already have a ~/.ssh/id_rsa.pub just type "ssh-keygen -t rsa" and keep hitting enter until it's done :) Just use this code to easily enable passwordless login with SSHD key=`cat ~/.ssh/id_rsa.pub`;ssh user@192.168.5.25 "echo $key >> ~/.ssh/auth........

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........

XMPP Chat Protocol using Jabber - Guide Tutorial Setup Linux Chat Server

In Debian based distros: apt-get install jabber Reading package lists... Done Building dependency tree Reading state information... Done The following packages were automatically installed and are no longer required: fakeroot dkms Use 'apt-get autoremove' to remove them. The following extra packages will be installed: jabber-common The following NEW packag........

Picking an FTPD (vsftpd) Server in Linux Centos/Debian

I decided on using yum to help me decide even though I normaly use proftpd I decided to see what else I could find. yum search ftp Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * rpmforge: ftp-stud.fht-esslingen.de * base: mirrors.netdna.com * updates: updates.interworx.info * addons: yum.singlehop.com * extras: mirrors.netdna.com rpmforge........

Bash Script Info

Bash Script Infohttp://www.faqs.org/docs/Linux-HOWTO/Bash-Prog-Intro-HOWTO.html#ss10.5 http://www.scit.wlv.ac.uk/~jphb/spos/notes/shell/shell5.html http://quong.best.vwh.net/shellin20/#LtohTOCentry-41 http://www.cactus.org/~dak/shellscript.html http://db.ilug-bom.org.in/Documentation/abs-guide/ http://pegasus.rutgers.edu/~elflord/unix/bash-tute.html http://heather.cs.ucdavis.edu/~matloff/UnixAndC/Unix/CShellII.html Since bash i........

Adventures in pre-paid SIM Cards and data GPRS/Edge/3G in China with China Mobile in Shenzhen, Guangzhou, Shanghai, Beijing and other cities

This really is a difficult and confusing process for non-Mandarin speakers, but here's what I've done and learned so far: You can purchase an "M-Zone" China Mobile pre-paid SIMCard from almost anywhere but I tried to purchase mine from Suning (a large electronics dealer) hoping they would be able to help me or answer my questions but my plan didn't work out at all. At Suning once I found someone who spoke some English they gave me the 55 RMB M-Zone China Mobile P........

sudo: Error dropping capabilities, aborting in Linux Centos 5.3

For some reason Ikeep getting this error when trying to run a sudo command eg: sudo -u someuser somecommand sudo: Error dropping capabilities, aborting My version of sudo is:sudo-1.6.9p17-3.el5_3.1 and I've heard that version 1.7 fixes everything. The only thing is yum does not think sudo has any update. Iguess the new version has not been committed to the RPM repository yet. This is really a huge and ann........

How To Save iptables firewall rules Centos/Redhat/Fedora Linux

This is something that annoys a lot of people, fortunately the Redhat style OS's are the most simple in this respect. I disagree that Debian's way makes sense, it is more of a hackish approach in how they implement iptables. Anyway, for those who are using Redhat/Centos style OS's it is very simple. Set your rules from the shell/command prompt and to save the iptables firewall rules so they are remember/loaded on boot just run this command: service iptables........

iPhone/iTunes sync error "0xE8008001"

This happened during a sync of my iPhone while installing some apps. This usually happens to non-jailbroken iPhones who are trying to install non-Apple approved software OR jailbroken phones who haven't done the "Sync update". How to fix this error and get the Sync Update Open Cydia - Manage - Sources - Edit Add this source: http://cydia.hackulo.us Then under the section "Hackulo.us" install "Ap........

Samba SMB Error - Server not using user level security and no password supplied. tree connect failed: NT_STATUS_WRONG_PASSWORD

Server not using user level security and no password supplied. tree connect failed: NT_STATUS_WRONG_PASSWORD That happens when trying to use smbclient to connect to a share. The weird thing is that I can authnenticate just fine from Windows XP. It is partially my mistake, I forgot this share does have a password. I've tried authenticating with the correct user and also with "Guest" because this works in Windows. In Linux I ........

Writing/Burning a data CD-R/DVD-R or DVD+RW in Unix/Linux

There's a lot of outdated information and confusion for system administrator's out there. One annoying task for many an Administrator has been backing up data in Linux. You don't need any GUI tools such as K3B or GnomeBaker. Both are excellent tools but for veteran command line users working remotely, using the keyboard is a great and possibly automated way to save yourself pain and hassle. At a later date we'll cover how scripting can automatically backup certain........