sysctl vm.overcommit_memory=1
echo never > /sys/kernel/mm/transparent_hugepage/enabled
echo 511 > /proc/sys/net/core/somaxconn
1:M 26 Nov 2023 21:34:33.840 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.
1:M 26 Nov 2023 21:34:33.840 # Server initialized
1:M 26 Nov 2023 21:34:33.840 # WARNING overcommit_memory is set to 0! Background sa........
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.........
When Is It Time to Leave Your VPS, VDS, and Dedicated Server Provider?
Choosing the right hosting solution—be it Virtu........
We used a simple Debian 10 VM and showed the memory before starting docker and with no docker containers being started. The goal is to show much much memory dockerd actually uses.
Before docker was started
The VMwas using 58M of RAM.
After docker was started
it was using 99MB of RAM.
How much RAM does docker use?
It's not scientific but fair to say dockerd itself uses about 41MB of RAM (99-58).........
This article about migrating to a CentOS 7 /8 RAID mdadm array has a lot of info but I wanted to focus specifically on what newer versions of CentOS 7 require to boot mdadm and what changes are necessary on CentOS 7.8+
CentOS 7 / 8 mdadm RAID booting requirements
This assumes you are chrooting into an existing install or using it to get a new deployment ready. However, these steps can........
Bonding is an excellent way to get both increased redundancy and throughput. It is similar to the "Network Teaming" feature in Windows.
There are a few different modes but we will use mode 6, I think it's the best of both worlds, as it is not just a failover, but it provides round robin, so you will get redundancy and load balancing. So if you have a 1G single port, you will have a combined throughput of 4G at this point. Just bear in mind that the true thr........
In our 2024 VPS Server/Cloud Buyer's Guide, we place the location of your VPS/hosting/server as one of the priorities that is often overlooked.
2024 Update - Datacent........
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........
yum -y install gcc make gperf genisoimage flex bison ncurses ncurses-devel pcre-devel augeas-devel augeas readline-devel
checking for cpio... cpio
checking for gperf... no
configure: error: gperf must be installed
configure: error: Package requirements (augeas >= 1.2.0) were not met:
Requested 'augeas >= 1.2.0' but version of augeas is 1.0.0
yum remove augeas augeas-libs augeas-devel
wget http://downl........
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........
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:........
So say you are behind a typical NAT/LAN setup whether at home, work or while travelling. What if you have a computer or server that you need to connect to from the outside?
Yes you could use a VPN but a quick and dirty, temporary and secure way is to use SSH's Reverse Tunneling Proxy feature.
Requirements
On the remote ssh server host you need the GatewayPorts option enabled in sshd_config (be........
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.........
#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........
This guide will work for most modern Linux versions like Centos RHEL 7, Debian, Mint, Ubuntu etc...
In Centos 7 the days of editing the "kernel"line and adding "single"are gone. On top of that sometimes after a new install passwords do not work, maybe you forgot your password or for some other reason you need to break in or fix your system? It could also be because you can't mount your root / or some other /etc/fstab error and many other err........
Install requirements:
yum -y install gmp-devel mpfr-devel libmpc-devel glibc-devel glibc-devel.i686 zip unzip jar
Download, untar, configure, compile and install GCC
http://mirrors.kernel.org/gnu/gcc/gcc-5.5.0/gcc-5.5.0.tar.gz
tar -zxvf gcc-5.5.0.tar.gz
cd gcc-5.5.0
./configure
make
make install
Now you need to cleanup th........
The solution is simple this happens if you don't meet the requirements. In my case PHP 5.4 was required but I had PHP 5.3 installed. Once I installed a newer version the install of PHPBB was successful.........
pip install obfsproxy
/usr/lib/python2.6/site-packages/pip/_vendor/requests/packages/urllib3/util/ssl_.py:90: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning.
InsecurePlatformWarning
You are using pip version 7.1.0, however version 8.1.1 i........
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........
I never did get it working, it is too bad as obfsproxy should really be an option and integrated into the OpenVPN client and server or something similar:
yum -y install python-pip python-devel
No package python-pip available.
#install the EPEL repo
python-pip install obfsproxy
python-pip install obfsproxy
-bash: python-pip: command not found
pip install obfsproxy
&........
-------------------------------------
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........
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........
Requirements:
1.) Enter your root wordpress directory.
2.)Download the latest wordpress.zip to it.
#backup your current files just in case
cp -a . wp-current-bk`date +%Y%m%d`
unzip wordpress-3.7.1.zip
rm -rf wp-includes
rm -rf wp-admin
echo y|cp -a wordpress/wp-includes .
echo y|cp -a wordpress/wp-admin .
echo y|cp -a wordpress/wp-content/* wp-content
echo y|cp wordpress/* .........
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........
I found this technique listed in many places which shows you how to use a common Linux tool "dd" to dump the raw partition of your iPhone.
I give credit to this site for showing me the correct way to dd from the iPhone, I never thought to try it in the other direction:http://log.ijulien.com/post/182804914/iphone-3gs-data-recovery
Requirements
1.) Jailbreak your........
Everyone says there is a "manual" way of doing it and then they tell you to use iTunes, but if you're like me, you're travelling on business in a foreign country and your laptop does not have iTunes and you don't have a way of getting it and/or don't want it.
For this example I'm using the provider "du" in Dubai, UAE (United Arab Emirates) but this method works for virtually all providers.
The requirements in this case to truly "manually update........
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........