![8vl3onvznkopxa6ny9995yrc4gw[1]](https://i0.wp.com/www.krazyworks.com/wp-content/uploads/2021/10/8vl3onvznkopxa6ny9995yrc4gw1-175x150.jpg "Awk & sed Snippets for SysAdmins")
Articles in SysAdmin
Using YUM to Sync Packages with Master Server
I just built a new CentOS box and needed to make sure it had all the same packages installed as one of my other servers. If you need to set up your own web server …
Check Filesystem Mount Status
Sometimes you just need to do a quick sanity check on the filesystem mount status to make sure everything in fstab is mounted and everything’s that mounted is in the fstab. If, like myself, you’re a fan …
Atop Script with Scheduling and Logging
When something is going down on a server, the first thing most sysadmins will run is the venerable top utility. This happens automatically: if you suspect the server is being sluggish, your fingers just type top without you …
Nohup Without Nohup.out
This is a common question: how can I run nohup without creating the annoying nohup.out ? And the common answer is: you can’t. But this is not exactly true.
Socket Statistics ss Command
This is a small collection of useful ss (written by Alexey Kuznetsov of the Russian Nuclear Research Institute) syntax examples that go beyond the basics covered by other sources. Here’s one I use often: it shows established connections to …
Filesystem Synchronization with Freehold
Whenever an application description begins with phrases like “runs on anything” and “is easy to setup”, attribute such bravado to the author’s lack of experience outside his development sandbox. Freehold comes as a tarball for “any Linux” …
Osync and DiffTree
Think of osync as a kind of rsync that is more suited for making backups. While rsync certainly has more options, osync takes a lot of the complexity out of writing a backup script with a few options that are …
Improving Your Scripts with ShellCheck
Unlike most other popular scripting languages, Bash has few style-checking utilities. The best one, I think, is ShellCheck – a very cool and useful utility that can greatly enhance robustness of your scripts. Like that time …
Increasing Entropy Pool in Linux
The pool of random numbers in Linux is derived primarily from user interaction (keystrokes and mouse movement). A server does not have such a source and the random pool may start running low, especially during …
Fixing NIC Name in Cloned VMWare Linux Machines
A suspected bug with certain versions of VMware ESX causes cloned Linux VMs to obtain a sequentially-number NIC. For example, if the parent VM had eth0, the clone will have eth1, and the clone of …
Better ‘date’ Functionality in Solaris
The Solaris date command does not have many of the useful features of its GNU equivalent. A workaround is to use Tcl. This requires tclsh to be installed (which tclsh). You can implement this workaround as …
Create NFS share from QNAP CLI
In this example we create the “test” NFS share on a QNAP NAS from CLI and export it to client_ip_01 and client_ip_02. Things to keep in mind: this only creates an NFS share – not …
Speed Up Shell Loops Using Arrays
Just a quick note on addressing a common issue of running redundant commands when using shell loops. Let’s say you needed to get a count of network connections to an Oracle database server for each connection …
Kodi Volume Control Stops Working
All of a sudden, when using the remote (either radio or IR), Kodi sound controls stop responding. The volume level does not change and the mute button doesn’t work. These are possible symptoms of an …
VMWare VMDK Locked Error
So, being a Unix admin on-call for the week, I just spent half of my Saturday fixing a dead Windows VM. Very annoying. The best I can tell, the issue occurred during the snapshot operation. …
Decrypting Mac Disk
It is generally a good idea to use full-disk encryption, especially on a laptop. However, this becomes bothersome if you are trying to re-partition your disk, say, to make the system dual-boot. Here’s a quick …
Useful Bash One-Liners
Here’s a loosely-organized pile ‘o shell quickies I kept googling now and then and finally decided to write ’em down.
Monitoring NetBackup Daemons
Here’s an example of a script you can use to monitor NetBackup server daemons in a Linux environment. The main difficulty with keeping track of these services is that there are so many of them. …
Using JTR to Crack Office Documents
John the Ripper is a free multi-platform password-cracking software. This article is not intended to be a comprehensive guide to jtr, rather a quick how-to. Starting with version 1.7.9, jumbo patch 6, jtr supports password …
Finding Prime Numbers
I have no intention of competing with GIMPS. To me this is a fun scripting exercise that may produce useful results beyond this initial application. Our goal is to take a bunch of integers and …
Counting Beer Calories
It is safe to say that almost everyone knows that sodas and other sugary drinks are bad for your teeth. Did you know that alcohol is bad for your teeth, too?
ALCOHOL INCREASES CAVITY RISK
Alcohol increases …
Monitoring Application Network Connections
A Java application on one of my servers has been causing problems by opening up too many network connections and now closing them quickly enough. I needed to be notified when the number of connections …
![wyryr1sn52gntzn65v4fpz5lc6v[1]](https://i2.wp.com/www.krazyworks.com/wp-content/uploads/2021/08/wyryr1sn52gntzn65v4fpz5lc6v1-80x80.jpg "Plundering Facebook Photo Albums")
![clfud46mxf2t5zph2l04zlpgl1d[1]](https://i2.wp.com/www.krazyworks.com/wp-content/uploads/2021/08/clfud46mxf2t5zph2l04zlpgl1d1-80x80.jpg "Scraping a Web Page in Bash")
![DSCF5361[1]](https://i1.wp.com/www.krazyworks.com/wp-content/uploads/2020/10/DSCF53611-80x80.jpg "Processing Videos with ffmpeg and Lightroom")
![Cat-Devouring-A-Bird-Pablo-Picasso[1]](https://i0.wp.com/www.krazyworks.com/wp-content/uploads/2020/10/Cat-Devouring-A-Bird-Pablo-Picasso1-80x80.jpg "Searching Twitter")
![91ebozy1e3b138waujy28agrngy[1]](https://i2.wp.com/www.krazyworks.com/wp-content/uploads/2021/08/91ebozy1e3b138waujy28agrngy1-80x80.jpg "Generating Random Text Files for Testing")
![iwoau71okwxqh4jv3k4ook32qps[1]](https://i2.wp.com/www.krazyworks.com/wp-content/uploads/2021/08/iwoau71okwxqh4jv3k4ook32qps1-80x80.jpg "Finding Cron Jobs")
![5gtysva4wkc8mzc1k3e66vaycxx[1]](https://i1.wp.com/www.krazyworks.com/wp-content/uploads/2021/08/5gtysva4wkc8mzc1k3e66vaycxx1-80x80.jpg "Understanding Memory Utilization in Linux")
![sy2zeb1vp2h8itlxfbbylw0jrm0[1]](https://i0.wp.com/www.krazyworks.com/wp-content/uploads/2019/12/sy2zeb1vp2h8itlxfbbylw0jrm01-80x80.jpg "Validating HTTPS Cache Peers for Squid")
![Photo-2019-10-07-14-39-03_0266[1]](https://i1.wp.com/www.krazyworks.com/wp-content/uploads/2019/11/Photo-2019-10-07-14-39-03_02661-80x80.jpg "Verifying SNMP Connectivity on Multiple Hosts")
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