Run this, which will cause the computer to continuously compress random data: dd if=/dev/urandom | gzip -9 >> /dev/null & To terminate the artificial workload, kill the running job you created. This assumes you have no other jobs running: kill %1 To check what jobs you have running in your shell: jobs -l
Category: Tech Blogs
blog
Find Which SSL/TLS Versions and Ciphers Are Supported For A Host
Hey folks, check out one of these if you want to see what ciphers are support by a host: nmap –script ssl-enum-ciphers -p 443 dahost.mynetwork or maybe one of these to check for specific protocols: openssl s_client -connect dahost.mynetwork:443 -tls1 ayyyy Mm.,
Setup Database Master/Master Replication on MySQL Server
Starting on DB01 cat /etc/my.cnf [mysqld] log-bin=mysql-bin server-id=1 replicate-wild-do-table=replicateddb.% replicate-ignore-db=test [mysqld_safe] err-log=/var/log/mysqld.log pid-file=/var/run/mysqld/mysqld.pid Restart the service to apply the changes service mysqld restart Login to MySQL mysql –u root –p Create replication user account with the host set to the Slave Server’s IP. Make sure the password is 32 characters or less! mysql> CREATE USER… Continue reading Setup Database Master/Master Replication on MySQL Server
Metadata file does not match checksum CentOS/RHEL/ScientificLinux
Greetings Traveler, I get various errors sometimes when running updates or installing a new package using the yum command. Usually cleaning the yum cache fixes it: yum clean all Mm.,
Fix CVE-2014-3566 on multiple Apache web servers with Perl
What if you have a bunch of configuration files to update in order to fix POODLE: SSLv3 vulnerability (CVE-2014-3566) ? If you don’t have a configuration management system to help with this, you could use an easy perl one liner which you’ll see can come in handy in a ton of situations. Specifically, we’ll be looking… Continue reading Fix CVE-2014-3566 on multiple Apache web servers with Perl
Install mod_security in Apache httpd for CentOS/RHEL/Scientific Linux
mod_security is an Apache plugin which is a good way to prevent malicious attacks on your web application and even just using the base/default configuration from the EPEL repository rpm package gives a pretty decent rule set and helps with hardening your system. mod_security is all about rule sets and looking for specific types of… Continue reading Install mod_security in Apache httpd for CentOS/RHEL/Scientific Linux
How To Install The EPEL Repo on CentOS/RHEL/Scientific Linux 7, 6 and 5
CentOS 7: vmhacks.com]# wget https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm vmhacks.com]# rpm -Uvh epel-release-7*.rpm CentOS 6: vmhacks.com]# wget https://dl.fedoraproject.org/pub/epel/epel-release-latest-6.noarch.rpm vmhacks.com]# rpm -Uvh epel-release-6*.rpm CentOS 5: vmhacks.com]# wget http://dl.fedoraproject.org/pub/epel/5/x86_64/epel-release-5-4.noarch.rpm vmhacks.com]# rpm -Uvh epel-release-5*.rpm Enjoy Mm.,
Whitelist an IP using denyhosts in CentOS 6 RHEL 6
Hi there, Add your IP to this file and restart if you want to whitelist an IP in denyhosts: /var/lib/denyhosts/allowed-hosts Also make sure to check the /etc/hosts.deny file for the IP if it’s already been blocked. Then restart service denyhosts restart Yo Mm.,
Run a Command on Multiple Systems at once using Bash – CentOS/RHEL
Hey there friends, So there are tons of different methods out there for managing multiple systems. Configuration management, centralized command “senders” and the like (CFEngine, Puppet, Ansible, Chef). One quick and dirty way you can manage multiple systems without setting up anything fancy or new is just with a one line for loop in bash.… Continue reading Run a Command on Multiple Systems at once using Bash – CentOS/RHEL
Use rsync over ssh CentOS RHEL Scientific Linux Bash
Make sure you have rsync installed on both servers and then you can use it with ssh to sync remote directories in one line: cd /webroot/www rsync -avz -e ssh syncboy@FROMHOST:/webroot/www/vmhacks.com . enjoy. Mm.,