SUSE 15 SP4 Mini CD ISO

by Ramses Soto-Navarro ramses@sotosystems.com, 9/12/2022

Overview
Download and Mount ISO
Mount ISO Repo
Copy ISO Files
Create Custom Mini ISO
Boot to the Upgrade


Overview

Brief notes on how to create a 130MB mini CD or ISO, in order to run a release upgrade, from SUSE 15 SP3 to SP4, via a custom web mounted repository. This is a much better alternative than using the 13GB DVD ISO for a release upgrade, especially for VM machines. All previous repositories will be deleted. This steps were created using a Debian workstation. Audience is experienced Linux administrators.

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Upgrade Oracle Linux 7 to 8 Using Leapp

by Ramses Soto-Navarro ramses@sotosystems.com, 7/27/2022

Overview
Pre-install Steps
Run Leapp Pre-upgrade
Verify Version 8 Local Repo
Run Leapp Upgrade
Verify New OS
Remove Old Kernels


Overview

Brief notes on how to run an online upgrade of Oracle Linux 7 to 8 using Leapp. Audience is experienced Linux administrators.

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UEFI Recovery for Oracle Linux 7

by Ramses Soto-Navarro ramses@sotosystems.com, 7/26/2022

Overview
Create KVM Guest
Start SSH
Partition for UEFI
Format Partitions
Mount and Chroot
Reinstall UEFI Grub2
Initialize UEFI GRUB2
Rebuild the Boot Ramdisk
Last Tasks


Overview

Brief notes on P2V physical to virtual and back, Oracle Linux 7 migration, with UEFI secure boot included; useful for rescue or recovery of physical Linux servers that require UEFI. Here we migrate a physical Linux server to a virtual guest under Linux KVM. The same can be done with Linux version 8. The audience is experienced Linux administrators.

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Create Certificate Signing Request with Multiple Subject Alternative Names

by Ramses Soto-Navarro ramses@sotosystems.com, 2/8/2022

Overview
Create CNF
Create CSR
Verify CSR


Overview

Brief on how to create a certificate request with multiple subject alternative name.

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Squashfs Backup Demo

by Ramses Soto-Navarro ramses@sotosystems.com, 2/1/2022


Overview
Mount squashfs file
Interactive shell
Release session
Prepare Server for Backup
SSHFS remote mount
Squash Backup


Overview

What is squashfs:

  • Squashfs is an archiver like tar.
  • Archives data onto backup file.
  • Allows quick read access of file backups.
  • High compression.
  • Can be mounted.
  • Can be appended.
  • Random seek, rather than linear.
  • Very quick access.
  • Used in embedded systems, cellphones, routers, livecd.
  • 7-zip supports squashfs.

The squashfs mount enables us to:

  • Archive the entire old server in a compressed file.
  • Mount the squashfs file and easily review files and directories.
  • Copy files from the old servers.
  • Run an interactive shell session of the old server.
  • Append more files to the backup file as needed.

Audience is experienced Linux administrators.

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