Category Archives: Linux

Hard Drive Burn-in Testing

Hard Drive Burn-in Testing THIS TEST WILL DESTROY ANY DATA ON THE DISK SO ONLY RUN THIS ON A NEW DISK WITHOUT DATA ON IT OR BACK UP ANY DATA FIRST 1) Run a short test # smartctl -t short /dev/sdb 2) Run a conveyance test ??? # smartctl -t conveyance /dev/sdb 3) Run a… Read More »

Installing Visual Studio Code on RHEL

RHEL, Fedora, and CentOS based distributions We currently ship the stable 64-bit VS Code in a yum repository, the following script will install the key and repository: sudo rpm –import https://packages.microsoft.com/keys/microsoft.asc sudo sh -c ‘echo -e “[code]\nname=Visual Studio Code\nbaseurl=https://packages.microsoft.com/yumrepos/vscode\nenabled=1\ngpgcheck=1\ngpgkey=https://packages.microsoft.com/keys/microsoft.asc” > /etc/yum.repos.d/vscode.repo’ Then update the package cache and install the package using dnf (Fedora 22 and… Read More »

Cannot boot because missing external disk

See man pages fstab(5) and mount(8). Using the nofail mount option will ignore missing drives during boot. nofail Do not report errors for this device if it does not exist. So your fstab line should instead look like: UUID=6826692e-79f4-4423-8467-cef4d5e840c5 /backup/external ext4 defaults,nofail 0 0

Creating and extending Linux LVMs

Notes on how to create or add disk, volume groups and logical volume in Linux (RedHat) 1. First add disk to system by what ever means your system requires. 2. Find name of disk using fdisk # fdisk -l /dev/sd* | grep i ‘Disk’ For my examples below, it would have listed sdb but not… Read More »

RHEL Subscriptions

To be able to use YUM on an RHEL server you need to register it with the RedHat servers. NB: You can do this with a Developer account, which is free! First register the system # subscription-manager register –auto-attach that enter your username and password. or add –username=<username> –password=<password> onto the end of the above… Read More »

Yum groups

# yum groups list # yum groups info “Development Tools” # yum groups install “Server with GUI”

Setting up SSH to use key pairs

If you SSH to the same server a lot and don’t want to type the password each time you can configure SSH so you don’t have to. First login to your terminal as normal and run $ ssh-keygen This will ask you the name of the key pair file you want to use. It will… Read More »

SELinux and Ports

Here is an example of how ports are controlled by SELinux. Say that the port that apache uses was changed to 1000 when you start apache you get these errors [root@server01 conf]# systemctl status httpd httpd.service – The Apache HTTP Server Loaded: loaded (/usr/lib/systemd/system/httpd.service; enabled; vendor preset: disabled) Drop-In: /usr/lib/systemd/system/httpd.service.d └─php-fpm.conf Active: failed (Result: exit-code)… Read More »