A lot of times I've seen questions about how this works when you have multiple nodes or a CDN, it can be quite tricky in theory if you have random IPs or several IPs. The way certbot works at least for non-DNS challenges is that it will hit a random server that it resolves to, you have no control over which one it hits. If certbot hits node 1 at first to tell it to create the well-known file, then checks node 2 or any other node, you will find auhorization fails.........

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.........

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://........

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........

I have a Canon MF642c and the scanner wouldn't work. I tried to use saned but it didn't work with the BJNPlike it did for some other Canon models. Introducing sane-airscan with packages for the most common distributions: https://software.opensuse.org/download.html?project=home%3Apzz&package=sane-airscan http........

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........

yum -y install wget unzip wget https://download.nextcloud.com/server/releases/nextcloud-18.0.2.zip unzip nextcloud-18.0.2.zip yum -y install php php-mysqlnd php-json php-zip php-dom php-xml php-libxml php-mbstring php-gd mysql mysql-server Last metadata expiration check: 0:58:02 ago on Fri 13 Mar 2020 02:12:49 PM EDT. Dependencies resolved. ===================================================================........

If you just do a normal chown user.user somedir it won't work. You will see the ownership is still the previous owner. How To Change Ownership Of Symlink: The simplest part is just adding the -h which means no dereference so it applies the ownership on the symlink and does not try (and fail) to change ownership of the dereferenced symlink destination. chown -h user.user somedir........

The easiest way to know if your videos are playing with GPU acceleration are to watch the process of xplayer, mpv or whatever you are playing. The CPU usage should be no more than 10% for that process/program if it is using acceleration. Let's manually play with vdpau to make sure it works before we make it permanent: First make sure you have libvdpau installed: sudo apt install vdpau-driver-all If yo........

sudo pip3 install python-docx [sudo] password for : Downloading/unpacking python-docx Downloading python-docx-0.8.10.tar.gz (5.5MB): 5.5MB downloaded Running setup.py (path:/tmp/pip_build_root/python-docx/setup.py) egg_info for package python-docx no previously-included directories found matching 'docs/.build' warning: no previously-included files matching '.DS_Store' foun........

If you get error messages like this it is usually because /var/run/sshd does not exist. root@userbox:/# service sshd status ● ssh.service - OpenBSD Secure Shell server Loaded: loaded (/lib/systemd/system/ssh.service; enabled; vendor preset: enab Active: failed (Result: start-limit-hit) since Wed 2019-04-10 02:24:44 EDT; 1 Process: 511 ExecStartPre=/usr/sbin/sshd -t (code=exited, status=255)........

Pass QEMU this flag: -soundhw ac97 Or you could use (for a Ensoniq soundcard): -soundhw es1370 However on some machines I get this error: pulseaudio: pa_simple_new for capture failed pulseaudio: Reason: Connection terminated pulseaudio: pa_simple_new for capture failed pulseaudio: Reason: Connection terminated audio: Failed to create voice `ac9........

Below are the common errors you'll get with named AKA bind if your time is incorrect. The simplest solution is to install and run ntpd to correct your system's time (install ntpd if it is not installed) systemctl start ntpd systemctl enable ntpd Dec 20 13:36:16 hostingbox named[2169]: error (no valid DS) resolving 'develop.waxrain.com/A/IN': 14.215.150.17#53........

You can find many ways to specify the VLANin your network configuration but Ifind this is the simplest and quickest. In this case we are talking about a bridged adapter "vmbr0" but it works even if you just had a normal non-bridged interface. The key here is that in vmbr0 you'll notice there is no IP address. We just specify "manual". Below it is a similar stanza for "vmbr0.58" in this case 58 represents the VLAN (change........

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: ........

Done on Centos 7.3 very important as clearly based on older guides it was a lot easier and more simpler! Hint do not use grub2-install! If you have trouble booting after this check this CentOS mdadm RAID booting/fixing guide. One huge caveat if you are an oldschool user or sysadmin who has avoided UEFIbooting The nor........

This is mainly the case on Centos but applies to other distros and situations. If you are running programs in the background with the &, at least in Centos it is usually not honored and if you quit or are disconnected the backgrounded programs will be sent sighup and be shut down. The simplest way around this instead of using & is to start any programs or commands with "nohup" Eg. nohup yourscript.sh........

Simple solution install python-dev sudo apt-get install python-dev libyaml-dev libpam-dev........

Say you have a path like this "/some/path/here with spaces/". If you try to transfer it you will get a message along the lines of: scp -rp 192.168.0.12:"/some/path/here space/" . scp: /some/path/here: No such file or directory scp: space: No such file or directory You can escape each space but what a pain that is especially if you have multiple spaces in the path. The simplest way is to use the follow........

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........

This happens all the time, you are reading from a textfile which has spaces eg: datainfo 00 datainfo 11 If you do loop on it like this: for info in `cat $file`; do echo "info=$info" done It will treat datainfo and 00 as two separate lines: info=datainfo info=00 Obviously that's not what we want and there are many weird solutions in bash bu........

Use imagemagick: convert -density 200 file.pdf file.jpg Increase the "density" value to get a higher resolution/larger file an decrease it to go smaller. This is really the quickest and simplest way. Some issues you may have: http://realtechtalk.com/ImageMagick_Convert_PDF_Not_Authorized-2217-article........

I right clicked all applicable cells and chose "number" but that's enough. I notice when I click the cell there is an invisible ' in front of the number: '33.64 Calc imported my CSV and decided to add a ' in front of the numeric currency values!!!*Actually the problem occurs when you right click the cells and change the type from text to number, no matter what format you choose. If I change it to be currency i........

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

Out of memory: kill process 7559 (rsync) score 635 or a child Killed process 7559 (rsync) I was surprised to see this in my dmesg whenmy rsync backup suddenly stalled/stopped. This system has 3 gigs of RAM and lots of free memory so I don't understand what is happening. rsync invoked oom-killer: gfp_mask=0x200d2, order=0, oomkilladj=0 Pid: 7600, comm: rsync Not tainted 2.6.24.2 #83 [] oom_kill_pr........

You can find it for free at http://nginx.org/ I find nginx is simpler to setup than pound (it's not hard but I found it unintuitive and annoying), it seemed to make some basic setups overly complicated with the config file syntax. nginx on the other hand is perfectly suited in everyway, it is even simpler to setup and seems to be the most stable and most efficient any load balancer. I would go as far as to say that a good nginx setup is more relia........