Generate strong SSH private keys
June 2019 update: altered the rounds from 96 to 192. After living with 96 for a couple years, the delay was no longer noticeable, so I moved to a higher Continue Reading…
Category: Linux
Blocking outgoing ports with firewalld
I’m guessing the lack of useful examples for nearly anything firewalld-related is a testament to how few people use it; ugh. Anyway, had a customer server that had a malfunctioning Continue Reading…
Using a Thales nShield Connect 6000 on CentOS
Here’s my play by play for installing a Thales nShield Connect network-based HSM into a CentOS linux environment: # echo ‘PATH=$PATH:/opt/nfast/bin’ > /etc/profile.d/nfast.sh # exec bash mount -o loop /root/SecWorld-linux64-user-12.10.01.iso Continue Reading…
Excluding packages from yum-cron auto update on RHEL 7 / CentOS 7
So in RHEL 6 / CentOS 6, there is of course the yum-cron package which will let your system auto update. Generally, you don’t want to auto update kernel packages. You’d Continue Reading…
Kickstarting with RedHat’s (in)consistent network device naming
If you’ve installed RHEL/CentOS 7, then you’ve probably encountered the now-default ‘consistent network device naming’ feature. The goal is to eliminate what, in theory, is the unpredictable nature of network Continue Reading…
rsyslog unresponsive and netstat Recv-Q building?
Recently had an issue where servers were randomly seeming to hang, or slow down significantly. I isolated the problem to activities that had a mandate to log something to syslog Continue Reading…
Building NTPD 4.2.8 on RedHat 7.3
Let me guess; you had an ancient RedHat 7.3 server sitting around that was acting as an NTP server, so you’ve of course never replaced it because why bother, it Continue Reading…
Finding the source of website hacks
If you’re involved in web hosting, you’re probably also involved in cleaning up hacked websites; especially if you have users running WordPress, Drupal or Joomla, which are all notorious for Continue Reading…
Cron job to dump all mysql databases daily
If you use MySQL as part of your web hosting operation, which of course everyone does, you’ve probably run into your share of requests from customers to restore data. This Continue Reading…
Using rsync over ssh when the remote side is a chroot shell
Just a tip; the rsync download listed later in this article works on VMware ESXi too! October 2020 Update: This process continues to work for vSphere since Vmware continues to Continue Reading…