This command creates a full system backup using tar, with special options to preserve ownership, ACLs, and extended attributes. Let’s break it down:

🧾 Full Command

tar --numeric-owner --xattrs --acls -cvpzf /mnt/backup/system.tar.gz \
  --exclude=/mnt/backup --exclude=/proc --exclude=/sys \
  --exclude=/dev --exclude=/run /

🧩 Option-by-option breakdown:

Option Meaning
tar The command-line archiving tool
--numeric-owner Save numeric user/group IDs instead of names (important for restoring on different systems)
--xattrs Include extended file attributes (like SELinux labels or user-defined metadata)
--acls Include Access Control Lists (fine-grained permission info)
-c Create a new archive
-v Verbose — show files being processed
-p Preserve file permissions
-z Compress the archive using gzip
-f /mnt/backup/system.tar.gz Output file path for the archive

🚫 Excluded Paths

These are excluded because they are dynamic, pseudo, or would cause issues if archived:

Path Reason for Exclusion
/mnt/backup Prevent backing up the archive itself recursively
/proc Virtual filesystem — no real files to back up
/sys Kernel info — also virtual and dynamic
/dev Device files (sockets, pipes, etc.)
/run Runtime system files (e.g., PID files)

🗂️ Target

  • The final / means: archive the entire root filesystem.

  • It creates: /mnt/backup/system.tar.gz

🧠 Usage Notes

  • Run as root (sudo) to ensure access to all files.

  • You can later restore with:

sudo tar --xattrs --acls -xvpzf system.tar.gz -C /

Make sure to boot into rescue or live mode before restoring the root FS.