![8vl3onvznkopxa6ny9995yrc4gw[1]](https://i0.wp.com/www.krazyworks.com/wp-content/uploads/2021/10/8vl3onvznkopxa6ny9995yrc4gw1-175x150.jpg "Awk & sed Snippets for SysAdmins")
Books have been written on the subject of awk and sed. Here’s a small sample of commands I put together over the years that are useful for everyday system administration tasks. Most of these tasks …
Read the full story »Removing CTRL-M from Unix Files
This is a simple but annoying and persistent problem: text files edited on Windows and the uploaded to Unix acquire the “^M” character at the end of each line. In my experience, this little problem …
Observium Agent Installation on Pidora
Just some quick notes on installing Observium agent on Raspberry Pi running Pidora. Pretty much the same process applies to any Fedora-like flavor.
Log Event Time Distribution
When “once in a while” answer is insufficient and you need to know exactly how often a particular event occurs on the system, there are a few easy things you can try from command line.
A Better Mysqlcheck Script
Mysqlcheck is a stand-alone MySQL utility for checking, optimizing and repairing tables. It’s a useful tool that allows automating the usually time-consuming database maintenance tasks. One of the advantages of mysqlcheck it is ability to run …
Late Night Rant #26
When you’ve ls’d, grepped, catted, piped and tailed everything on your computer and there is absolutely nothing left to do, there’s always this…
Protected: Raspberry Pi 2 and OpenELEC/Kodi Configuration Notes
There is no excerpt because this is a protected post.
Login Monitor
Sometimes after a couple of beers I start feeling paranoid. I make sure the door is locked and check my firewall logs. Here’s a very basic script to monitor your server’s login record and notify you about …
IMDB Lookup Script
IMDB is one of the most complete movie and television databases on the Internet. It offers an advanced Web search UI, but Unix CLI support has been discontinued years ago and the old scripts no …
Ad-Hoc Analysis of /var/log/secure
The /var/log/secure contains a record of authentication and authorization activity on the system. It can be an invaluable resource for the purposes of intrusion detection and prevention. Below are a few simple examples that show how …
Salt Configuration Notes
Here are just some random notes on installing and configuring salt-master and salt-minion services. I figured I better write this down before I forget. Most of this is covered in official documentation, but in a very nonchalant …
Installing Salt Minion on RHEL5
As of recently, python26-distribute has been removed from EPEL5 due to lack of support and attempting to install salt-minion on RHEL5 will throw a dependency error. If you are still running RHEL5, you would need …
Salt Snippets
SaltStack has decent documentation (at least compared to Puppet), but it’s a bit lacking on examples. There’s plenty of simple stuff that is useful if you’re managing a handful of nodes. However, why would you …
Late Night Rant #25b
No sooner than I stopped complaining about HP’s “holy” Web site, I ran into a similar issue with Red Hat’s site. And that doesn’t happen very often. Unlike HP, Red Hat folks tend to take better …
Late Night Rant #25: HP’s Web Site Fail
I’ve already mentioned my dislike for the epic mess of broken links HP gingerly called its Web site. Nearly a year-and-a-half later the situation did not improve. Actually, it might have gotten worse.
Memory Utilization-by-User
Here’s a useful one-liner (sort of) that will show you memory utilization details by user ID on Linux (RHEL, Fedora, CentOS) systems. This may come in handy when trying to figure out who is eating …
Late Night Rant #24: North Korean Internet
Today was the day the North Koreans would have learned they had the Internet and the Americans DDOSed it. Unfortunately, they had no Internet, poor bastards. But, as long as this keeps us entertained… Hey, …
Late Night Rant #23: Kim The Sony-Slayer
Sony execs are shedding crocodile tears over the latest IT security breach that brought substantial financial losses to the company. Let’s not dwell on the trivial: who did it and why are irrelevant technicalities. How …
RHEL/CentOS Yum Operations
The Yellowdog Updater, Modified has more features than most of us will ever need. Below are some hopefully useful examples that will help keep your system maybe secure by replacing old known bugs with new …
VSFTPd, SSL, and Firewalls
If you ever wanted to configure SSL/TLS encryption for an FTP server behind a firewall, the “Google wisdom” ranges from “a major pain” to “can’t be done”. Fortunately, things are not all that bad. In …
Using Pflogsumm Postfix Log Analyzer
Pflogsumm is an oldie but a goodie. It’s a Perl script that sifts through your Postfix server maillog and provides you with a neat summary of events and some statistics. This information can be useful …
Visualizing Apache Logs with Logstalgia
The Logstalgia is a cool graphical utility for visualizing the Apache access_log files. The practical value of Logstalgia is debatable, but it’s entertainment value is not in question. The managers and NOC operators can stare …
Sending Attachments Using Mailx
Sometimes it’s just better to attach a file to your email than to “cat” the contents into the email body. Later versions of mailx support the “-a” option for handling attachments. With the older mailx …
Commands & Shells »
Awk & sed Snippets for SysAdmins
![8vl3onvznkopxa6ny9995yrc4gw[1]](https://i0.wp.com/www.krazyworks.com/wp-content/uploads/2021/10/8vl3onvznkopxa6ny9995yrc4gw1-80x80.jpg "Awk & sed Snippets for SysAdmins")
Books have been written on the subject of awk and sed. Here’s a small sample of commands I put together over the years that are useful for everyday system administration tasks. Most of these tasks …
Synology NAS Hacks
![rhd3hj6zvnqeth7qo8em0alduj0[1]](https://i2.wp.com/www.krazyworks.com/wp-content/uploads/2021/10/rhd3hj6zvnqeth7qo8em0alduj01-80x80.jpg "Synology NAS Hacks")
I’ve been using various Synology NAS devices for many years now, and they’re great. Well, almost. There are a few rough spots that don’t thrill me. These consumer-grade devices are designed to be difficult to …
Applications »
Synology NAS Hacks
I’ve been using various Synology NAS devices for many years now, and they’re great. Well, almost. There are a few rough spots that don’t thrill me. These consumer-grade devices are designed to be difficult to …
WordPress: Post-processing of the image failed
![ytioq398kc1wnvvz95uixhcn5ii[1]](https://i2.wp.com/www.krazyworks.com/wp-content/uploads/2021/08/ytioq398kc1wnvvz95uixhcn5ii1-80x80.jpg "WordPress: Post-processing of the image failed")
This particular WordPress issue appeared with version 5.3 and is refusing to go away. However, the problem here is not with WordPress but with the Apache ModSecurity. The particular ModSecurity rule in question is 200003 …
Data »
Synology NAS Hacks
I’ve been using various Synology NAS devices for many years now, and they’re great. Well, almost. There are a few rough spots that don’t thrill me. These consumer-grade devices are designed to be difficult to …
Finding Duplicate Photos
![9dwz62kvm0gtjya9kwb7pawtk9y[1]](https://i2.wp.com/www.krazyworks.com/wp-content/uploads/2021/10/9dwz62kvm0gtjya9kwb7pawtk9y1-80x80.jpg "Finding Duplicate Photos")
Being a shutterbug and a digital hoarder can get expensive. A couple of days ago, my
TerraMaster D5-300 5-bay DAS crashed. Again. This time it was the power supply. I replaced it only to discover that …
Monitoring »
NFS I/O Stats with Logging
![tq9mhhd5xy2q0kto2j1785n6odv[1]](https://i1.wp.com/www.krazyworks.com/wp-content/uploads/2021/10/tq9mhhd5xy2q0kto2j1785n6odv1-80x80.jpg "NFS I/O Stats with Logging")
The nfsiostat is an excellent tool for analyzing NFS performance. The only major problem with this utility is that it’s designed to be used interactively. It does not have logging or timestamping capabilities. I needed …
Finding Cron Jobs
![iwoau71okwxqh4jv3k4ook32qps[1]](https://i2.wp.com/www.krazyworks.com/wp-content/uploads/2021/08/iwoau71okwxqh4jv3k4ook32qps1-80x80.jpg "Finding Cron Jobs")
Cron is an indispensable tool for system administration. The difficulties in working with cron in a large environment stem from its decentralized nature. Cron jobs multiply like rabbits, and keeping track of them is not …
Networking »
NFS I/O Stats with Logging
The nfsiostat is an excellent tool for analyzing NFS performance. The only major problem with this utility is that it’s designed to be used interactively. It does not have logging or timestamping capabilities. I needed …
Inventorying NFS Mounts and Mount Options
![4ucne6vs8m7hqdl0el9ddqd1sql[1]](https://i2.wp.com/www.krazyworks.com/wp-content/uploads/2021/10/4ucne6vs8m7hqdl0el9ddqd1sql1-80x80.jpg "Inventorying NFS Mounts and Mount Options")
As time goes by, NFS mounts multiply like rabbits. Added by many different people over the years, these entries present a dizzying variety of mount options – most are a copy-paste job that makes little …
Editor
Igor
Sr. Unix SysAdmin with twenty years experience supporting Solaris, HP-UX, AIX, IRIX, and Linux servers in a large distributed environment.
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