Your frontend CDN (eg. Cloudflare or even your own load balancer/proxy) must be sending the X-Forwarded-For and you must be running Apache on the backend.
This solves the problem where your logs and services will only see the proxy/CDN IP and not the real client IP.
mod_rpaf will fix all of this
This solution transparently sets the real IP of the client for Apache and any services that rely on........
In a lot of distros, vdpau which accelerates video through the GPUis often not installed even in recent distros. This will result in Firefox with Youtube dropping frames when you check the "Stats for Nerds" and to the eye as jerky or slower video playback due to the dropped frames.
Some sites will say that because you are watching VP09 that there is no GPU support, but with vdpau installed and enabled, many GPUs will still be able to use hardware decoding for 4K........
In a lot of distros like Debian, ecryptfs will mount itself in /home/yourusername/Private
This is controlled by Private.mnt which may contain the mount path like this:
/home/yourusername/Private
Change the default mount location of ecryptfs by modifying this file:
home/.ecryptfs/yourusername/.ecryptfs/Private.mnt
After you unmount and relogin, you should find ecryptfs is now mo........
A lot of developers want to go to 3.11 because of the speed improvements, but most distros never have the latest Python version.
Using the deadsnakes third party repo is the easiest way aside from compiling it yourself (which is safer and recommended):
Step 1 - Add the repo
apt-add-repository ppa:deadsnakes/ppa
If you get an error about requests then install it:........
Why choose OpenVPN instead of a firewall appliance?
OpenVPN can be a reliable and easy replacement for traditional hardware or just be an additional tool that your company uses so that the firewall can focus on its job rather than acting as a VPNappliance at the same time.
When comparing OpenVPN with traditional firewal........
One simple flag to configure will create a makefile that statically links all the shared objects and embeds them instead the binary execute. This means as long as you have the same architecture that things should run.
Eg. if you have an old version of Debian with a different version of glibc, then this will solve that problem.
./configure LDFLAGS="-static"
To test that it is really statically linked run ldd:
ldd src/wget........
Most newer distros inexplicably cause your NIC to have what Icall "random" non-standard name conventions because of systemd.
This is a big problem for many people and especially those running servers. Imagine that you have a static IPconfigured for ens33 but then the hard disk is moved to a newer system, the NIC could be anything from ens33 to enp0s1, meaning that manual intervention is required to go and update the NIC config file (eg. /etc/network/interfa........
I used to believe that for Desktops especially that the "ondemand" CPUfrequency changing that kernels included with Ubuntu and Debian based distros have would be sufficient for snappy performance.
However, you can feel the lack of performance on the fastest computer if you have ondemand. A lot of times even under high load 100% of your CPUfrequency in MHz will not be used.
For example a 2.8Ghz CPUmay only run at 1.8MHz or even .9GHz. Now........
chroot which stands for change root allows you to virtually operate in another operating system even though you haven't booted it. It is commonly used to deploy new distros, applications and to fix a broken Linux/Unix install or prep a new system image without having to physically boot the drive or disk.
So in this example let's say we have a drive that has a Linux OS installed on /dev/sdb1 and we have mounted this partition on /mnt/sdb1
The key point is to edit the &quo........
The net-tools command brings back all of the oldschool tools that we're used to:
/bin/netstat
/sbin/ifconfig
/sbin/ipmaddr
/sbin/iptunnel
/sbin/mii-tool
/sbin/nameif
/sbin/plipconfig
/sbin/rarp........
To remove all spaces from all files in the current directory
linux rename remove spaces
rename "s/ //g" *
how to replace part of the text with another (it is almost like using sed):
rename s/"Screenshot at 2019-04-22 "/"AC97-Windows-InstallSolution"/g *
The first part "Screenshot at 2019-04-22" is what we're looking for
The........
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........
Now many people report this card simply not working in various Linux distros and kernels. My issue is different, it always works at 100mbit (eg. plugged into a 100mbit switch) but no matter what 1000M/gigabit switch I would try, it would never work.
The link would be up (the lights were on) and the OS detected the link as being up as well but it wouldn't work at all and could not pass data in or out (not even a ack/ping).
There is one simple solution and command........
Say you have a bunch of files like this:
file-01.jpg
file-02.jpg
...............
What if you want to mass rename them?
the rename tool can work just like sed
For Debian based distros:
Note "file" is what we search for and "newname" is what we replace it with, so substitute according to your requirements.
rename s/file/newname/ name-file-*.jpg
For R........
Have you ever unplugged the wrong drive and then had to rebuild the entire array? It may not be a big deal in some ways but it does make your system vulnerable until the rebuild is done.
Many distros often enable the "bitmap" feature and this basically keeps track of what parts need to be resynced in the case of a temporary removal of a drive from the array, this way it only needs to sync what has changed.
To enable bitmap to speed up rebuilds and sync........
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........
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........
This is very annoying, the only known fix is to install vim
apt-get install vim
After that everything works as normal.........
Warning: Unable to open /dev/fd0 read-write (Read-only file system). /dev/fd0 has been opened read-only.
That's a very annoying error, it's simply because Centos for some reason thinks it's wise to load the "floppy" kernel module, who has a floppy drive? I haven't seen or used a floppy for over 12 years!
It's more than just annoying, if you probe the drives attached to your system, eg. with grub or partprobe, it keeps trying to locate a flopp........
Use "ImageMagick" which can be installed easily on most UNIX/Linux distros.
Remember that it will go with the standard file listing to determine the order but I believe you can manually specify multiple jpg's in the arguments.
Convert image/jpg to PDF
convert *.jpg yourpdf.pdf
This is a very handy and free tool.
Convert DOC/TXT documents to PDF
If you wanted to convert a .doc file or text........
I couldn't figure out whyI couldn't install a simple package. This is what's annoying about cutting edge Debian distros, yes we know you support each license on average for 1-2 years but why take down the supporting binary packages and basically disable the older versions?
sudo apt-get install update
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Couldn't find p........
I've never understood how to enable and disable services for different run levels in Debian based distros, it's just weird, annoying and doesn't make sense. I much prefer chkconfig from RHEL.
Just install the package called 'rcconf' and be done with it. rcconf makes things easy for you.
apt-get install rcconf
Reading package lists... Done
Building dependency tree
Reading state information... Done........
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 &........
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........
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........
FreeBSD Desktop OSsI would probably choose these over Linux.
In many ways these are probably more stable and just as easy to use as any Linux distros but the benefit of stable, updated and secure packages!
PC-BSD - http://www.pcbsd.org
DesktopBSD - http://www.desktopbsd.net/index.php?id=37
Personally PC-BSD is Beta at this point and is not easy if you are installing it on a non-primary partition.
I have not used Deskt........
top - 09:34:12 up 2 days, 20:57, 2 users, load average: 1.83, 1.99, 2.03
Tasks: 59 total, 2 running, 57 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.3%us, 0.0%sy, 0.0%ni, 0.0%id, 99.7%wa, 0.0%hi, 0.0%si, 0.0%st
That 99.7% wa is iowait, it means the server is waiting for a process to complete an IOoperation or in plain English, there is a delay in........
In Newer Linux Distros This Way Is Easiest and works on newer versions like Ubuntu, Mint, Fedora, Centos, Debian etc.
#if you are missing timedatectl this in newer distros like Ubuntu/Mint/Debian and are using a container like Docker then do "apt install systemd"
timedatectl set-timezone America/Vancouver
Replace the America/Vancouver with the correct timezone.
To see the list you can just type "timedatectl set........