• hostapd example configuration for high speed AC on 5GHz using WPA2


    This example is using RTL8821AU chipset from a TP-Link T2U Plus USB adapter and other similar ones should work the same. Here's how to get this chipset RTL8821AU working in Linux. Here's how to get RTL8812 and RTL8822 working in Linux.........
  • apache2 httpd apache server will not start [pid 22449:tid 139972160445760] AH00052: child pid 23248 exit signal Aborted (6) solution Mint Debian Ubuntu Redhat


    If you get this error, it is often because you have configured Apache with modules that weren't actually installed. Eg. you try to load the PHPmodule but didn't actually install the apache2 php module, so the server can't start. In general, this error can often be caused by issues with problematic modules and/or Apache being configured for modules that have not actually be installed (eg. libapache2-mod-php) is missing. The above results in this less than obv........
  • AH01630: client denied by server configuration:


    This happens when upgrading to Apache 2.4 from 2.2 or just because you don't have the right permissions set which we'll get into. You need this in the ........
  • How To Install OpenProject on Centos 7 Step-by-Step Guide


    There are a few caveats that may not be obvious to everyone so I am going to cover them here but keep this in mind before starting. Before starting install epel or you will be missing tesseract: yum -y install epel-release #1) When you specify your SSL certificate with a full path, it really needs to exist where you tell it to (including the default location of /etc/ssl/certs and /etc/ssl/c........
  • apache symlinks denied even with followsymlinks


    Symbolic link not allowed or link target not accessible: /path/httpdocs/news.html There are a few reasons that can cause this message and this is for people who have ruled out the basics, eg. your symlinks are enabled and the right permissions are applied (but read on to learn about ownership requirements above the directory in question). So there are a few key things here that cause Apache not to follow symlinks:........
  • How To Use Letsencrypt SSL/TLS Encryption to Create Certificates without installing on the target machine


    For some reason, perhaps you don't want to run a daemon or let Letsencrypt have access to your production server. There is a way to use it like a normal CSR/CA setup in manual mode. ./letsencrypt-auto certonly --manual -d realtechtalk.com - www.realtechtalk.com   Eventually you will get prompted to create a certain path and file with certain data: Create a file containing just this data: Casdfasfadsfsad........
  • Proxmox error uploading an iso solution


    Error 0 occurred while receiving the document root@vh1:/var/tmp# wget http://mirror.compevo.com/proxmox/proxmox-ve_5.2-1.iso --2018-08-30 16:27:37-- http://mirror.compevo.com/proxmox/proxmox-ve_5.2-1.iso Resolving mirror.compevo.com (mirror.compevo.com)... 103.25.61.44 Connecting to mirror.compevo.com (mirror.compevo.com)|103.25.61.44|:80... connected. HTTP request sent, awaiting response... 200 OK Length: 641517568 (612M) [application/o........
  • Debian Mint Ubuntu compiling xmr-stak


    sudo apt-get install libcurl4-openssl-dev git build-essential autotools-dev autoconf libcurl3 sudo apt-get install libcurl4-gnutls-dev git clone https://github.com/wolf9466/cpuminer-multi sudo apt-get install cmake libpthread-* libmicrohttpd-dev libssl-dev libhwloc-dev git clone https://github.com/fireice-uk/xmr-stak-cpu.git make install cd bin chmod +x xmr-stak-cpu ./xmr-stak -O xmr........
  • [warn] VirtualHost 10.2.5.101:443 overlaps with VirtualHost 10.2.5.101:443, the first has precedence, perhaps you need a NameVirtualHost directive


    [root@thetor2017 conf]# service httpd restart Stopping httpd: [ OK ] Starting httpd: WARNING: MaxClients of 3000 exceeds ServerLimit value of 300 servers, lowering MaxClients to 300. To increase........
  • SMF Forums / Simple Machines Forums Not Displaying Images Theme or Styles Properly using 127.0.0.1


    This is one thing that has me wondering about SMF. It is apparently a known issue but in the latest version and new install nothing looked right because it was using http://127.0.0.1 to find everything! How on earth would it ever do this or think it is normal? Excerpt of crazy html code it produces that causes the issue: ........
  • Apache htaccess Custom ErrorDocument not working properly for root home page 403 Error Issue and Solution


    So I have a domain "testdomain.com". Inside test domain.com's root is the following .htaccess: Options +FollowSymLinks -Indexes ErrorDocument 403 /launch/index.html Order Deny,Allow Deny From All Allow From 192.168.1.2 When you visit anything other than root things work fine. Eg. if you visit http://testdomain.com/somedirfile.html It will show the right error in /launch/........
  • "Object of class WP_Term could not be converted to string"


    Normally when I've seen this it's when you are using a variable like a normal string when in fact it's actually an array such as this example: [Tue Mar 13 04:22:35 2018] [error] PHP Catchable fatal error: Object of class WP_Term could not be converted to string in /vhost/httpdocs/wp-content/plugins/wp-instagram-post/classes/class-woo-igp.php on line 578 &nbs........
  • Installing SSL Certificate with Chain Intermediary CA File


    Some of the cheaper or newer SSL suppliers will require this to work properly (otherwise you may be prompted that the cert is invalid when it's not the case but it will certainly scare off your users!). In the Apache vhost conf for the domain here is what you add: SSLCACertificateFile /path/to/your/cafile.pem Here is a full example of an SSL Vhost config in Apache using a CA Certificate file ........
  • vbulletin 4.2.5 after upgrading from 3.6 white screen fatal php errors


    The code may lead you to believe you have an incompatible template but if you are not trying to use an old template currently that is not the issue. I actually deleted all 3.x style templates to make sure. What the issue is, is old plugins that are not compatible but Vbulletin does not seem to account for this except that you'll see a fatal PHPerror. You should disable all plugins and then enable one by one until you find the one that is causing the issue. &........
  • ffmpeg Linux Mint download, compile and install howto


    #if you have nvidia make sure you install the nvidia-cuda-toolkit so hardware acceleration can be used wget http://ffmpeg.org/releases/ffmpeg-3.3.2.tar.bz2 tar -jxvf ffmpeg-3.3.2.tar.bz2 cd ffmpeg-3.3.2/ ./configure --disable-yasm install prefix /usr/local source path ........
  • phpBB3 slow and internal dummy connection


    Using Apache 2.2 and PHP5.6 PHPBB3 is very slow to respond. Actually for some reason it takes so long to even register a log entry in access_log as in several seconds or a few minutes later it shows up in Apache. All other vhosts and Apache access stops working and freezes until the request to access PHPBB3 slowly completes. It seems to randomly be slow if you stop using it whether for posting or reading the forums. I've migrated to different machines including........
  • HTML files in Apache still displaying as raw text even with DefaultType, ForceType etc.


    There was only one solution here and it was the following: edit /etc/httpd/conf/httpd.conf Comment the lines for the Mime Magic Module: # MIMEMagicFile /usr/share/magic.mime # MIMEMagicFile conf/magic *Don't forget to restart Apache and clear your browser cache twice I was using DefaultType and ForceType a........
  • Apache Vhost HowTo Serve Same Content using a different domain and IP


    There are a few ways of doing this and all basically involve using the reverse proxy or "ProxyPass" feature of Apache to accomplish it. 1.) Create a normal vhost and simply symlink the root directory of the site you want to mirror. Eg. originalsite.com and newsite.com /vhosts/originalsite.com/httpdocs You would symlink like this: ln -s /vhosts/originalsite.com/httpdocs vhosts/originalsite.com/........
  • openvz yum problem Centos 6.5 cannot find file on mirror:


    #solution Edit /etc/yum.repos.d/openvz.repo For the first two entries comment out #mirrorlist and uncomment #baseurl and then it worked openvz yum problem Centos 6.5 cannot find file on mirror: yum update Loaded plugins: fastestmirror Determining fastest mirrors * openvz-kernel-rhel6: mirrors.ustc.edu.cn * openvz-utils: mirrors.ustc.edu.cn base ........
  • 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........
  • dir2slideshow Centos rpm requirements


    yum -y install dvdauthor ffmpeg mjpegtools sox bc rpm -ivh dvd-slideshow-0.8.4-2.noarch.rpm Preparing... ########################################### [100%] 1:dvd-slideshow ########################################### [100%] /usr/bin/dir2slideshow: line 553: bc: command not f........
  • Webalizer Error Error: Unable to restore run data (11) Error: Unable to restore run data (11) Solution


    Error: Unable to restore run data (10) Error: Unable to restore run data (11) Ikeep getting this error but so far there is no obvious solution. Sometimes I've had to remove the *.hist files so I'll try that again. *Update This is an ongoing random problem after months of running webalizer it runs into some problem that can only be fixed by removing the following files so it can rebuild the stats (you end up losing p........
  • heartbeat compile errors with rpmbuild


    c1: warnings being treated as errors stonith_signal.h:34: error: 'stonith_signal_set_simple_handler' defined but not used gmake[3]: *** [apcmaster.lo] Error 1 gmake[3]: Leaving directory `/root/rpmbuild/BUILD/heartbeat-1.2.4/lib/plugins/stonith' gmake[2]: *** [all-recursive] Error 1 gmake[2]: Leaving directory `/root/rpmbuild/BUILD/heartbeat-1.2.4/lib/plugins' gmake[1]: *** [all-recursive] Error 1 gmake[1]: Leaving directory `/root/rpmbuild/BUI........
  • Centos Howto Upgrade to PHP 5.3 from 5.2


    It's not as simple as "yum install" as you can see below and it doesn't stop there. yum install php53 Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * rpmforge: mirror.us.leaseweb.net * extras: centos.mirror.rafal.ca * updates: centos.mirror.nexicom.net * base: centos.mirror.nexicom.net * addons: centos.mirror.nexicom.net Setting up Install Process........
  • rpmforge Centos 6 how to install


    rpm --import http://apt.sw.be/RPM-GPG-KEY.dag.txt i686: rpm -ivh http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.2-2.el6.rf.i686.rpm x64: rpm -ivh http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.2-2.el6.rf.x86_64.rpm ........
  • Apache SNI is not needed what is the issue?


    Iread this article and still don't understand the issue. If I understand correctly the client negotiates after the first SSLconnection and then gets the correct hostname and thus correct certificate. http://wiki.apache.org/httpd/NameBasedSSLVHostsWithSNI To their credit I know I'm not using SNIbecuase Iget this message in the Apache log :) [warn] Init: You should not use name-based virtual hosts in conjunction with SSL!! B........
  • Centos 5,6,7 Install EPEL from Fedora for extra packages Howto


    http://fedoraproject.org/wiki/EPEL#How_can_I_use_these_extra_packages.3F Visit the above URL, choose your version and architecture and install it. EPELhas a lot of missing and extra packages that rpmforge does not. For old versions of EPEL that are deprecated, eg.........
  • LSI MegaRAID Adventures, Guide and HowTo


    LSi Megaraid At first it was configured as a RAID 0, then I deleted the Virtual Disk Group. I thought both drives would be shown and detected in Linux as sda and sdb but it actually shows nothing. To make them work you have to hit Ctrl+R before the system boots (when prompted) and create a Virtual Disk Group. In my case I created each one as RAID 0 (with a single drive only) as I just wanted JBOD but there is no such option or default in these Dell Pe........
  • rpmforge Centos 6 x64 howto install


    rpm --import http://apt.sw.be/RPM-GPG-KEY.dag.txt rpm -ivh http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.2-2.el6.rf.x86_64.rpm Retrieving http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.2-2.el6.rf.x86_64.rpm Preparing... ########################################### [100%] 1:rpmforge-release #############........
  • package kernel-xen-2.6.18-274.7.1.el5.x86_64 is intended for a x86_64 architecture solution


    package kernel-xen-2.6.18-274.7.1.el5.x86_64 is intended for a x86_64 architecture Linux etc 2.6.18-274.7.1.el5xen #1 SMP Thu Oct 20 17:06:34 EDT 2011 x86_64 x86_64 x86_64 GNU/Linux As you can see above architecture and kernel is 64-bit but I had to force it to install using "--ignorearch" Solution #rpm --ignorearch -ivh kernel-xen-2.6.18-274.7.1.el5.x86_64.rpm Preparing...&nb........
  • Apache SSL Change Default SSL Vhost and Listening Port for SSL


    vi /etc/httpd/conf.d/ssl.conf Change the following from "Listen 443" to something like below Listen 2243 Then find the SSLVirtual Host Context and edit like below (to your new listening port) ## ## SSL Virtual Host Context ## ........
  • Centos 6 RTL8111/8168B r8169 link up and down error solution/fix


    02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 03) For whatever reason it seems the r8169 driver that ships and has shipped with most Linux distros for years is still flawed and does not work properly on these cards, causing 100mbit connectivity when it should be 1gbit and even worse, causing random network dropouts. The r8169 driver in Linux kernels is simply not meant to be used on th........
  • 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........
  • Error code: sec_error_unknown_issuer Solution Valid SSL Certificate Throwing Error in Firefox


    So you've just purchased your SSL cert, renewed it and installed it or maybe you've had it installed and working fine all the time with all other browsers but you've upgraded to a recent version of Firefox and suddenly get the warning "Error code: sec_error_unknown_issuer" error. This is terrible since if you bought an SSL cert, you are most likely using it for trust purposes for your business and obviously that message will scare away most potential customers.........
  • Apache High CPU Usage Enable Mod_Status Guide Solution - Find Cause of High CPU Usage Script/Domain


    mod_status is a great way to track down the source of high CPU usage and to find what vhost/script is the cause of it. It gives you a live view of bandwith usage, CPU usage, and memory usage broken down by domain/vhost and script/URI. Enable mod_status vi /etc/httpd/conf/httpd.conf ExtendedStatus On SetHandler server-status Order Deny,Allow Deny from all All........
  • monit example tutorial how to enable status checking and manipulation


    You need to enable the httpd daemon with monit to actually view the status and control, it's not only for the web interface since the httpd is theONLY way of controlling monit and viewing the status. monit monitor all will also reinstate disabled services if they've timed out too much. Just restarting the service will do nothing to re-monitor a service that monit has stopped monitoring due to too many failures. *Also note that /etc/monit.conf i........
  • 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&........
  • 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........
  • Apache Forbidden You don't have permission to access / on this server.


    Forbidden You don't have permission to access / on this server. [Sun Jan 23 15:28:12 2011] [crit] [client 96.44.31.12] (13)Permission denied: /www/vhosts/domain.com/httpdocs/.htaccess pcfg_openfile: unable to check htaccess file, ensure it is readable Solution I've done a chmod 755 .htaccess and index.php and restarted Apache That wasn't the only issue, the issue was the httpdocs direc........
  • php won't work with absolute links


    php won't work with absolute links Warning: imagecreatefromgif(/images/header.gif): failed to open stream: No such file or directory in /vhostsdir/httpdocs/images.php on line 15 That is how my path is structured and ONLY likes the true full path as /vhostsdir/httpdocs/images/header.gif Why can't it work relative to the vhost directory with absolute links just like say an html link would.........
  • 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.........
  • [function.vB-Registry-include]: failed to open stream: No such file or directory in /www/vhosts/site.com/forums/includes/class_core.php on line 2394


    [function.vB-Registry-include]: failed to open stream: No such file or directory in /www/vhosts/site.com/forums/includes/class_core.php on line 2394 This happens on a new vBulletin install where you haven't created the config.php file. Simply copy the config.php.new file into config.php and you'll be good to go.........
  • How not to change an IP address in CPanel during a migration


    /usr/local/cpanel/bin/swapip domain(s) It simply doesn't work, the Apache VHOSTS remain 100% unchanged, why does this script exist? I'm sure it would work from the control panel but I am locked out because my IP was changed and it doesn't match the CPanel license. I wish CPanel would make it easier to update the license IP. I even took it a step farther, I manually edited the vhosts and restarted Apache and it........
  • 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.........
  • Canel Default VHOST DocumentRoot/Contents Directory is /usr/local/apache/htdocs


    This can be very annoying and CPanel doesn't seem to document it, or it's not found or made as obvious as it should be. It's always funny when I find it more difficult to work with a control panel than to do everytihng manually without CPanel or even Plesk. So once again, the default serve path for contents is: /usr/local/apache/htdocs and this is especially applicable when accessing Apache by just an IP which is unbound to any domain at this point.........
  • 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........
  • OpenVZ backup container to a single file while it's running using "vzdump"


    Proxmox has made this free utility to backup running OpenVZ containers. It's a great program which is actually just a PERL script but gets the job done. This program is not 100% required because all it really does is cp -a from your container's path as far as I know but it is still good to have uniformity to how you backup your containers. For RPM distros such as Centos/RHEL/Fedora etc.. download and install this: wget http://www.proxmox.com/cms_proxm........
  • Norton Antivirus is the worst - who would have known?


    Norton Antivirus is the worst - who would have known?http://www.software-antivirus.com/ Check the link above, that review site lists Norton as one of the ones to stay away from. With good reason too, I always wondered why Norton seemed to miss so many viruses, spyware and such. Even when it didn't, it was absolutely useless because it was either unable to delete the file and it was never able to repair or disinfect. So in essence, from my experience, N........
  • Process/Parse PHP from HTML files using .htaccess and allowoverride


    RemoveHandler .html .htmAddType application/x-httpd-php .php .htm .html Just add the above into the .htaccess file for your website. Also remember that you need to be allowed to override the Apache and this should go into the vhost for your site as shown below: # you need the AllowOverride otherwise .htaccess directives will be ignoredOptions FollowSymLinksAllowO........
  • Apache/Mod_SSL not serving the right/expected certificate?


    There is actually by default a "Default SSL" vhost that can mess things up for you and can cause surprising and unexpected results. Default Apache SSL Cert in /etc/httpd/conf.d/ssl.conf there is a default SSL Virtual Host which screws things up by offering itself instead of the SSL cert I specify in my own vhosts........
  • Create/Enable SSL Certificates for Apache on Linux/Unix Systems eg. Redhat,Centos,Debian


    Shortcut/Easiest Way To Create A Self-Signed Key: openssl req -new -x509 -nodes -days 1530 -out server.crt -keyout server.key Using the above, you instantly create a self-signed certificate valid for 1530 days and you can simply skip to step #5.) below. If You Need a Real SSLCertificate (eg. Equifax/Openssl) then you need to create a CSR request (you'll need to follow Steps 1.) and 2.) in order to create the CSR. You then upload the CSR Certi........
  • 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........
  • Apache Ignoring/Not processing .htaccess file


    I was getting very frustrated one day wondering why it appeared my .htaccess file was being ignored and not processed by Apache. No matter what I did it was obvious that Apache didn't care about my .htaccess file. Then I realized that the default settings must be in effect, which is that my vhost didn't explicitly allow me to override the default settings. This usually comes down to your vhost settings. Make sure you have an entry like this in your Apache vhost settings in........
  • 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........
  • Latest Articles

  • How high can a Xeon CPU get?
  • bash fix PATH environment variable "command not found" solution
  • Ubuntu Linux Mint Debian Redhat Youtube Cannot Play HD or 4K videos, dropped frames or high CPU usage with Nvidia or AMD Driver
  • hostapd example configuration for high speed AC on 5GHz using WPA2
  • hostapd how to enable and use WPS to connect wireless devices like printers
  • Dell Server Workstation iDRAC Dead after Firmware Update Solution R720, R320, R730
  • Cloned VM/Server/Computer in Linux won't boot and goes to initramfs busybox Solution
  • How To Add Windows 7 8 10 11 to GRUB Boot List Dual Booting
  • How to configure OpenDKIM on Linux with Postfix and setup bind zonefile
  • Debian Ubuntu 10/11/12 Linux how to get tftpd-hpa server setup tutorial
  • efibootmgr: option requires an argument -- 'd' efibootmgr version 15 grub-install.real: error: efibootmgr failed to register the boot entry: Operation not permitted.
  • Apache Error Won't start SSL Cert Issue Solution Unable to configure verify locations for client authentication SSL Library Error: 151441510 error:0906D066:PEM routines:PEM_read_bio:bad end line SSL Library Error: 185090057 error:0B084009:x509 certif
  • Linux Debian Mint Ubuntu Bridge br0 gets random IP
  • redis requirements
  • How to kill a docker swarm
  • docker swarm silly issues
  • isc-dhcp-server dhcpd how to get longer lease
  • nvidia cannot resume from sleep Comm: nvidia-sleep.sh Tainted: Linux Ubuntu Mint Debian
  • zfs and LUKS how to recover in Linux
  • [error] (28)No space left on device: Cannot create SSLMutex Apache Solution Linux CentOS Ubuntu Debian Mint