Linux for Everyone

Recently there was another Vulnerability grab My attention which was related to DES and Tripple DES (3DES) , Any men in the middle can exploit this vulnerability by capturing large amount of encrypted data and thus recover plain text sensitive data. Severity : Medium CVE Number : CVE-2016-2183 For Freelance Work & Queries Contact me by Email Id support@linuxforeveryone.com Remediation : You need to disable any ciphers starting with DES and 3DES supported by Server by any service present on server for example Apache Nginx etc   Important Point to Remember : 1 :   Normally old browser don't supports DES and 3DES ciphers. It is very important to note that in many cases, a software update (back-ported version provided by Operating System vendor ) won't be enough to resolve this issue. Usually software update doesn't overwrite manually tweaked configuration files, which means, DES/3DES can be still available, even if the software up

Recently World of Linux come across yet another bug which is haunting the nix users all over the world. This bug has given a name COW and its associated CVE number is CVE-2016-5195. Its kind of funny how this bug get their names, this too grab my attention when i first heard about it as COW ! i laughed out like what ? :) For Freelance Work & Queries Contact me by Email Id support@linuxforeveryone.com Background : later when I started reading about this bug in details got to know how this bug got his name, which nothing but a " copy-on-write " technique which Linux kernel uses to maintain the private read -only memory mapping and this technique have some flaws in it since 2007 woohooo that was way long back. In other words if i have to say is this bugs allow a server to become completely compromised through local privilege escalation. This vulnerability is specific to the Linux Kernel, and exploiting this vulnerability does require a local system user

In this Post, I am going to cover how to optimized REDIS  (recently i was reading this random blog giving more clear insight on what is redis and what the use of it in real world) instances as per our requirement. if you are not aware about REDIS at all, you can refer to my previous post where i have covered How To install REDIS on Centos/Redhat servers which goes here . How To Create Multiple instances of REDIS which goes here . What is the Best Standard method to configure REDIS which goes here . So, Lets see how to optimize our redis server. few points you need to keep in mind that which are important while doing optimization and we are going to learn more about shortly. For Freelance Work & Queries Contact me by Email Id support@linuxforeveryone.com Remove any errors you are seeing under redis logs Check the amount of cache size your site is using for each port Set proper eviction policy for redis keys Set proper kernel Settings to ma

In my earlier post i have covered how to run multiple instances of redis also showed through a video how it can done. In this post, I am going to cover best suitable redis (recently i come across this beautiful blog simplifying the concept of redis and its uses in real world) configuration file structure to have to minimize confusion to identify which ports belong to which cache. for example if you are having several ports configured for redis, how you will determine which port is associated with which redis cache.So in our case i.e redis with Magento, we normally used 3 types of cache Cache (magneto configuration files cache)  Full Page Cache Session Cache  So, to avoid confusion among the ports and its associated cache, i would recommend to use following data in your redis configuration for each port respectively as shown.   For Freelance Work & Queries Contact me by Email Id support@linuxforeveryone.com 1) Create a file with name redis-base.conf under /etc/ an

In the last post I have covered how to install redis server on Centos/Rhel using rpm method and yum method and some troubleshooting skills. In this post i am going to cover how to install and configure redis to run with multiple ports.                                                                           But why we need more ports ? If you have read my earlier post , you already know that by default redis runs on single port 6379, which any one can use it for small website to cache the data. But for heavy website like magento we need to use additional ports along with 6379 to serve different cache from different ports. Like in Magento there is simple cache which is normally stored under /var/cache directory. Then there is Full Page Cache which is stored under /var/full_page_cache and session cache which is stored under /var/session_cache. Note : Discussion about cache/full page cache/session is not under the scope for this document.                      

From this post, I am starting a series of posts/pages which will mostly based on caching (recently i read this blog and found out quite simple to understand about what and why we need caching) mechanism like Redis, Memcache, Apc, Varnish are the few to list. So, here on this post i am going to cover REDIS first. After reading this post, you will get to know                                                                                                                       What is Redis ? So, Redis is "no-sql" database which is used to stores data as keys. which is mainly used as database,as caching for website across the globe. NoSql means, there is no structure query language like mysql in redis, instead its data structure.                                                           Where it is Beneficial ? Many of the website are using redis to fasten their response time to the end user using the advantages of redis. So if you want your we

To clean the cache from system which apt caches when we update/install the packages apt-get clean    To downloads  packages list from repository and update them,to get data on latest available packages apt-get update   To install specific version of  package apt-get install package-name  To check OS version    Ex : lsb_release -a To provides the package's description, its dependencies, the name of its maintainer. apt search, apt show, aptitude search, aptitude show work in the similar manner Ex : apt-cache search php5-fpm The checkrestart program tries to determine if there are  processes  in the  system  that  need to be restarted after a system upgrade .Consequently, checkrestart is sometimes used as an audit tool  to  find outdated  versions  of  libraries  in  use, particularly after security upgrades Ex : checkrestart -h  List all installed packages, along with package version and short details. Ex : dpkg -l php5-fpm