When you run yum upgrade on a CentOS/RedHat 7 instance, you will be upgraded to 7.4. If you have a FreeRADIUS server, you will be upgraded from version 2 to 3, and your server will likely stop authenticating! Good times! Fortunately, the solution was not complicated for us, because we had good documentation. Symptoms Your […]
Warning: CentOS/RedHat 7.4 installs FreeRADIUS 3 with breaking changes Read More »
It can confusing when you have multiple persistent disks on an instance running on Google Compute Engine. For example, a server may have separate disks for the filesystem root, MySQL data, logs, and /tmp. Once you’ve created the Compute Engine disks and attached each one to the instance, how do you know which Compute Engine
Managing persistent disks on Google Compute Engine Read More »
The Historical Answer With Windows NT, prior to the advent of Active Directory, there was one Primary Domain Controller (DC) per domain, and every other DC was a Backup. The Modern Answer When Active Directory was introduced with Windows 2000, domain controllers became fully multi-master. There is no primary domain controller. However, there are two
Is there a “Primary Domain Controller” in Active Directory? Read More »
If you are a Linux or OS X power user, then you’re used to having all the necessary tools built into your OS. When you log into a Windows system (What! No command line?) you may feel lost. These tools and shortcuts will help you be productive on Windows systems. Windows Shortcuts Alt-x is a
Making Windows work for Linux and OS X admins Read More »
In Part 1, I summarized the basic concepts of SNMP and defined the terms and acronyms used in this post. Now, I will show how to use SNMP to monitor actual devices. As an example, I will monitor an enterprise-grade uninterruptible power supply (UPS) and power distribution unit (PDUs) from Tripp-Lite. These devices have an
Monitoring with SNMP, Part 2: Command-line tools for active SNMP Read More »
SNMP is a protocol for conveying information and controlling devices over a network. SNMP can be used in two ways: Active: a device sends a command to set a parameter or request information for another device Passive: a device sends an alert (called a trap) to another device, which is configured to receive traps and
Monitoring with SNMP, Part 1: Fundamentals of SNMP Read More »