Unbalance

Unbalance is a script designed for MergerFS users who also utilize SnapRAID. It ensures that a specified path of data resides on a single disk in the pool.

I wrote unblance to help migrate from an mfs create strategy to epmfs such that I could start using SnapRAID and never worry about hitting this quirk:

• https://sourceforge.net/p/snapraid/discussion/1677233/thread/8282fcf886/?limit=25#b71e/a288/884a/1d58.
• https://www.reddit.com/r/Snapraid/comments/1clk039/comment/l2zk8t3/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button

Features

• Ensures a specified path is located on only one disk.
• Automatically scans disks in the pool to find the largest existing data path.
• Moves data to the largest disk, if needed.
• Provides clear logging and operation status updates.

Installation

0. Make the script executable with chmod u+x unbalance.sh
1. Ensure you have rsync installed
2. Modify the disk list in unbalance.sh to match your mount points.

# Configurable Parameters
disks=("/mnt/disk1" "/mnt/disk2" "/mnt/disk3" "/mnt/disk4")  # Array of disk mounts

Usage

Run the script with the partial path you want to un-balance. Do not includ the disk or pool.

Example:

./unbalance.sh "tv/some-show (2024)"

For a path that is already un-balanced, you would see

Path: tv/show-a (2024)
-------------------
Logs: /home/azohra/unbalance.log (ID: 1MMQ7Y)
-------------------
Path Usage:
/mnt/disk1: Not present
/mnt/disk2: Not present
/mnt/disk3: Not present
/mnt/disk4: 7.2GiB (Largest)
-------------------
Total data to move: 0B
-------------------
Current operation: Checking data balance
-------------------
Recent Logs:
  [2024-06-23 19:37:24] [1MMQ7Y] 🟢 Unbalancer started for 'tv/show-a (2024)'
  [2024-06-23 19:37:24] [1MMQ7Y] Starting disk scan for path
  [2024-06-23 19:37:24] [1MMQ7Y] Path not present on /mnt/disk1
  [2024-06-23 19:37:24] [1MMQ7Y] Path not present on /mnt/disk2
  [2024-06-23 19:37:24] [1MMQ7Y] Path not present on /mnt/disk3
  [2024-06-23 19:37:24] [1MMQ7Y] Path present on /mnt/disk4: 7.2GiB
  [2024-06-23 19:37:24] [1MMQ7Y] ✔️ Path is already unbalanced (or does not exist on any disk)

For a path that requires un-balancing, you would see

Path: tv/show-b (2020)
-------------------
Logs: /home/azohra/unbalance.log (ID: eR4iA0)
-------------------
Path Usage:
/mnt/disk1: 3.6GiB
/mnt/disk2: 8.1GiB
/mnt/disk3: 4.3GiB
/mnt/disk4: 13GiB (Largest)
-------------------
Total data to move: 16GiB
-------------------
Current operation: Checking data balance
-------------------
Recent Logs:
  [2024-06-23 19:57:45] [eR4iA0] 🟢 Unbalance started for 'tv/show-b (2020)'
  [2024-06-23 19:57:45] [eR4iA0] Starting disk scan for path
  [2024-06-23 19:57:45] [eR4iA0] Path present on /mnt/disk1: 3.6GiB
  [2024-06-23 19:57:45] [eR4iA0] Path present on /mnt/disk2: 8.1GiB
  [2024-06-23 19:57:45] [eR4iA0] Path present on /mnt/disk3: 4.3GiB
  [2024-06-23 19:57:45] [eR4iA0] Path present on /mnt/disk4: 13GiB
  [2024-06-23 19:57:45] [eR4iA0] Path is largest on /mnt/disk4 with 13GiB
  [2024-06-23 20:12:55] [eR4iA0] 16GiB of data should move to /mnt/disk4
  [2024-06-23 20:12:58] [eR4iA0] Starting file transfer from /mnt/disk1 to /mnt/disk4
  [2024-06-23 20:13:17] [eR4iA0] Completed file transfer from /mnt/disk1 to /mnt/disk4
  [2024-06-23 20:13:17] [eR4iA0] Removed empty directories from /mnt/disk1:
  [2024-06-23 20:13:17] [eR4iA0] Starting file transfer from /mnt/disk2 to /mnt/disk4
  [2024-06-23 20:14:11] [eR4iA0] Completed file transfer from /mnt/disk2 to /mnt/disk4
  [2024-06-23 20:14:11] [eR4iA0] Removed empty directories from /mnt/disk2:
  [2024-06-23 20:14:11] [eR4iA0] Starting file transfer from /mnt/disk3 to /mnt/disk4
  [2024-06-23 20:14:40] [eR4iA0] Completed file transfer from /mnt/disk3 to /mnt/disk4
  [2024-06-23 20:14:40] [eR4iA0] Removed empty directories from /mnt/disk3:
  [2024-06-23 20:14:40] [k4ca6H] All files for 'tv/show-b (2020)' have been moved to /mnt/disk4
  [2024-06-23 20:14:40] [k4ca6H] ✔️ Path unbalanced successfully
-------------------

Logging

All actions are shown in the CLI and also logged to the directory where the script is executed, with the filename unbalance.log. The logs include detailed information about each step and operation performed by the script.

License

This project is licensed under the MIT License.