linuxexpert-practice-labs/labs/lfca/2-5-disaster-recovery

LFCA 2.5: Disaster recovery

A backup with tar and a restore, and a mirror to another machine with rsync over SSH.

Before you start

Work as root (sudo -i). The lab creates the directories /srv/projects and /srv/site with a few files, and user alice (password Lab-Pass-1).

The peer, at 10.99.0.2 (name peer), stands in for a second VM. It runs its own SSH server. It shares this VM's files and users, so what you copy to alice@peer:mirror/ lands in /home/alice/mirror here too, where you can compare it. Get a shell there with sudo ip netns exec lepeer bash.

Tasks

1. Back up /srv/projects to /root/projects.tar.gz with tar, delete /srv/projects, and restore it from the archive. Compare it with the original.
2. Install rsync if needed, and mirror /srv/site to the peer over SSH, as alice, into her home directory's mirror directory. Then change /srv/site/index.html and run it again, watching how little it copies.
3. Take a VM snapshot, delete something important, and roll back. Not graded.

Hints

• tar -czf /root/projects.tar.gz -C /srv projects, tar -tzf, rm -r, tar -xzf ... -C /srv. Keep a list such as find /srv/projects -type f | xargs sha256sum from before to compare.
• rsync -av /srv/site/ alice@peer:mirror/ (mind the trailing slashes); --stats or -v shows what it sent. ssh-copy-id alice@peer saves typing the password each time.
• Snapshots belong to the hypervisor (virt-manager, VirtualBox, your cloud console), not to the VM.