Show Logged In Users During a Time Window

Let's say you want to see who was logged in on the server during last weekend. This includes users who, say, logged in on...
When Was that Server Built?

When Was that Server Built?

Just a quick note on how to (sort of) figure out when a server first came online. This can be useful to various folks...
Deleting Lots of Files Quickly

Deleting Lots of Files Quickly

I am not talking about hundreds or thousands of files. I am talking about hundreds of thousands. The usual "/bin/rm -rf *" may work...
Bash and Expect Snippets

Bash and Expect Snippets

A small collection of maybe helpful examples of how to use expect with Bash. This is a very useful tool, especially when writing a...
Taking Linux Temperature

Taking Linux Temperature

Just some notes on setting up temperature monitoring and alerting on CentOS/RHEL running on HP ProLiant. The first step is to install lm_sensors: yum -y...
Find + Rsync + Xargs

Find + Rsync + Xargs

Just some quick syntax for running multiple rsync threads in parallel using find and xargs. In many cases (especially if NFS is involved)  this can...
Show NIC Bandwidth Utilization

Show NIC Bandwidth Utilization

Just a quick script that will measure bandwidth utilization in KB/s for all NICs on your server over the specified period of time. You can...
Diff on Output of Remote Commands

Diff on Output of Remote Commands

Let's say you run the same command on two remote servers and you want to compare the output. Here's a quick example: diff <(ssh -qtT...
Run Cron Jobs at Arbitrary Intervals

Run Cron Jobs at Arbitrary Intervals

Current versions of cron support sophisticated syntax making creating weird schedules a breeze. With older versions of cron you normally had to schedule multiple...