SLES: Search & install specific CVE

bschelst/ June 21, 2019/ Linux/ 0 comments

In SLES you can search & install specific CVE patches using the commands below.

Linux: “du” values don’t match “df” values.

bschelst/ February 16, 2019/ Linux/ 0 comments

If you do a df, and you compare those values with ‘du’, it is possible that those values don’t match. There are multiple reasons why this can happen, and one of those reasons if that files where deleted, but that the files are still in use by an application.In that case, it is possible that you need to stop/restart the

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Iptables: redirect port to other IP – port

bschelst/ November 20, 2017/ Linux/ 0 comments

You can use the following shell commands in order to redirect a port to another port.

Linux: simulate memory usage

bschelst/ November 14, 2017/ Linux/ 0 comments

Using the “stress” application, you can simulate high memory usage of your system.You may use the following command line:  

Mysql: script taking dump of all dbs

bschelst/ August 16, 2017/ Linux/ 0 comments

FFmpeg: decrease size of mp4 file

bschelst/ August 9, 2017/ Linux/ 0 comments

With ffmpeg you can also decrease the size (aka: quality) of a mp4 file on linux command line.You can use the following example, which will generate a +/- 5Mb file :

Jpegoptim: How to Optimize and Compress JPEG in Linux Commandline

bschelst/ August 9, 2017/ Linux/ 0 comments

You can optimize Jpeg images on linux command line (= reduce the size to load images faster).In order to achieve that, you can make use of the ‘jpegoptim’ application.On ubuntu/debian systems:   To optimize the jpeg file:

Denyhosts: Add IP to whitelist

bschelst/ August 7, 2017/ Linux/ 0 comments

Create a file ‘allowed-hosts’ in the ‘work_dir’ (can be found in the denyhosts.conf file), which is /var/lib/denyhosts on Ubuntu, containing the ip.See the example below:

Fail2ban: unblock an ip

bschelst/ August 7, 2017/ Linux/ 0 comments

Find IP Address to Unblock Log in to your server via SSH and type in the following command: iptables -L -n Look for the IP address you want to unblock / unban. Now we must find the jail name this IP address is in. To do so, type the following: fail2ban-client status unban the IP: fail2ban-client set ssh unbanip 192.168.1.1

Fail2ban: whitelist an ip

bschelst/ August 7, 2017/ Linux/ 0 comments

First, edit the config file : vi /etc/fail2ban/jail.conf Then, check the line : ignoreip = Add now add all ip you want. Each IP or range IP must be placed here with a space. Ex: 192.168.0.1 192.168.5.0/32 Save. And restart Fail2Ban: service fail2ban restart