SSH: Disable Host Checking for Scripts & Automation

In the world of Cloud Servers and Virtual Machines scripting and automation are top priority for any sysadmin. Recently while I was creating a script that logged into another server via SSH to run arbitrary commands, I ran into a brick wall. $ ssh 192.168.0.169 The authenticity of host '192.168.0.169 (192.168.0.169)' can't be established. ECDSA key fingerprint is 74:39:3b:09:43:57:ea:fb:12:18:45:0e:c6:55:bf:58. Are you sure you want to continue connecting (yes/no)? To anyone who has used SSH long enough the above message should look familiar....

 · 2 min · Benjamin Cane

Adding and Modifying Users and Groups in Linux

Adding and Modifying Users and Groups is a core systems administration task. The act of adding a user and group is fairly easy however there are some tricks that help make the long-term management of users easier. Tips for easier management Keep user attributes consistent amongst all systems A common mistake sysadmins make when building a new environment is they will allow uid's, gid's, home directories and other user attributes to be mis-matched from system to system....

 · 5 min · Benjamin Cane

mkisofs: Repackaging a Linux Install ISO

In the office I use Red Hat quite often and one of the quicker ways to provision a Red Hat server is via kickstart. There are many ways to reach a kickstart file during initial install (NFS, HTTP, FTP) but one of the ways I commonly use is to put the file on the installation DVD itself. The below steps are what I use to add a custom directory to the installation iso file....

 · 2 min · Benjamin Cane

ssh-keygen: Creating SSH Private/Public Keys

Are you tired of trying to memorize tons of passwords on different systems? Or do you simply want to have a faceless user SSH between two systems without being asked for a password? Well you are in luck because today we will be covering SSH keys. SSH Servers have the ability to authenticate users using public/private keys. In the case of pass-phrase less keys this allows users to ssh from one system to another without typing a password....

 · 3 min · Benjamin Cane

EMC PowerPath: superblock could not be read

Recently while working on a system that uses EMC PowerPath, I ran into a little issue after rebooting. The Issue fsck.ext3: No such file or directory while trying to open /dev/emcpowera1 /dev/emcpowera1: The superblock could not be read or does not describe a correct ext2 filesystem. The Cause The root cause of this issue is pretty simple when a Linux system boots it performs file system checks on file systems listed within the /etc/fstab file....

 · 2 min · Benjamin Cane