Fabrice Quenneville
feffc2920c
- Added sections for Information on Drives, Filesystem, Backup Procedures, Recovery, Drive Manipulation, Balances, Scrub, and Snapshots. - Included commands and procedures for listing drives, displaying filesystem information, managing backups, handling recovery, drive replacements, balancing, scrubbing, and snapshot operations. - Updated and standardized syntax highlighting and command format for clarity.
450 lines
9.2 KiB
Markdown
450 lines
9.2 KiB
Markdown
# BTRFS
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## Table of Contents
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- [BTRFS](#btrfs)
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- [Table of Contents](#table-of-contents)
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- [Information on Drives](#information-on-drives)
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- [Information on Filesystem](#information-on-filesystem)
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- [Backup Procedures](#backup-procedures)
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- [Recovery](#recovery)
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- [Drive Manipulation](#drive-manipulation)
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- [Replace Drives](#replace-drives)
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- [Balances](#balances)
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- [Scrub](#scrub)
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- [Snapshots](#snapshots)
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## Information on Drives
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**List of Drives and Mountpoints**
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To check all attached drives:
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```bash
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ls /dev/sd*
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ls /dev/nv*
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```
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To view mountpoints and drive details such as names, sizes, and mountpoints:
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```bash
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lsblk
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df -h
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cat /etc/fstab
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```
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**Drive Information**
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To get detailed information and serial number of a specific drive:
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```bash
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smartctl -i /dev/sdc
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```
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## Information on Filesystem
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**Show Basic Filesystem Information**
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To display basic information (size, IDs, paths, etc.) for the specified mountpoint:
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```bash
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btrfs fi show /mnt/media/
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```
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**Display Detailed Usage Information**
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To show detailed usage information (allocated, unallocated, etc.) for the specified mountpoint:
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```bash
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btrfs fi usage /mnt/media
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```
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**Display Detailed Allocation Information**
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To view detailed allocation information (block groups, used space) for the specified mountpoint:
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```bash
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btrfs fi df /mnt/media
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```
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**Get Detailed Device Usage Statistics**
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To get detailed device usage statistics (physical size, unallocated space, RAID levels, etc.) for a BTRFS filesystem:
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```bash
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btrfs device usage /mnt/media
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```
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**Scan and Display BTRFS Information**
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To scan and display BTRFS information for all devices or a specific drive:
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```bash
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btrfs device scan /dev/sda/
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```
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**Retrieve Statistics and Error Information**
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To get statistics and error information (read errors, write errors, flush errors, etc.) for the specified mountpoint:
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```bash
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btrfs device stats /mnt/media
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```
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**List BTRFS Subvolumes**
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To list BTRFS subvolumes:
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```bash
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btrfs subvolume list /
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btrfs subvolume list /home/fabrice
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btrfs subvolume list /mnt/workbench
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```
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**Default Subvolume**
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To check if a non-standard subvolume is set as the default:
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```bash
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btrfs subvol get-default /mnt/tmp/
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btrfs subvol list /mnt/tmp/
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```
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To change the default subvolume if a non-standard one is set:
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```bash
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btrfs subvol set-default 257 /mnt/tmp/
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```
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## Backup Procedures
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**Desktop Backup: Root and Home**
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1. Mount snapshot location:
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```bash
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mount UUID=394decca-4780-47c9-9ae3-e4d03681a791 -o subvol=snapshots /mnt/snapshots
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```
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2. Create snapshots for root and home:
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```bash
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btrfs subvolume snapshot / "/mnt/snapshots/root/2021-05-23 - Fedora 34 upgrade"
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btrfs subvolume snapshot /home "/mnt/snapshots/home/2021-05-23 - Fedora 34 upgrade"
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```
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3. Unmount after creating snapshots:
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```bash
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umount /mnt/snapshots
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```
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**Data Backup: Workbench, Documents, Education**
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1. Mount snapshot location:
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```bash
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mount UUID=72e1770a-9fc0-461e-88d3-db640ff53dd9 -o subvol=snapshots /mnt/snapshots
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```
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2. Create snapshots for multiple directories:
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```bash
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btrfs subvolume snapshot /mnt/workbench "/mnt/snapshots/workbench/2021-05-23 - Fedora 34 upgrade"
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btrfs subvolume snapshot /home/fabrice/Documents "/mnt/snapshots/Documents/2021-05-23 - Fedora 34 upgrade"
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btrfs subvolume snapshot /home/fabrice/Education "/mnt/snapshots/Education/2021-05-23 - Fedora 34 upgrade"
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```
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3. Unmount after creating snapshots:
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```bash
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umount /mnt/snapshots
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```
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**STOR1 Fedora Backup**
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1. Mount snapshot location:
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```bash
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mount UUID=e4fd608e-cfe8-4c10-b6d0-03b05bae8aa6 -o subvol=snapshots /mnt/snapshots
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```
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2. Create snapshot:
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```bash
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btrfs subvolume snapshot / "/mnt/snapshots/root/2021-06-06"
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```
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3. Unmount after creating snapshot:
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```bash
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umount /mnt/snapshots
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```
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**STOR1 Debian Backup**
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1. Mount snapshot location:
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```bash
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mount UUID=c9a77f3c-626f-47bd-b4e3-9a094bea287f -o subvol=snapshots /mnt/snapshots
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```
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2. Create snapshot:
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```bash
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btrfs subvolume snapshot / "/mnt/snapshots/root/2021-07-12 - post mostly setup"
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```
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3. Unmount after creating snapshot:
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```bash
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umount /mnt/snapshots
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```
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**STOR2 Backup**
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1. Mount snapshot location:
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```bash
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mount UUID=30bd5e0e-e781-4e87-8fb8-ea5606403b15 -o subvol=snapshots /mnt/snapshots
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```
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2. Create snapshot:
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```bash
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btrfs subvolume snapshot / "/mnt/snapshots/root/2021-06-06 - Fedora 34"
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```
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3. Unmount after creating snapshot:
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```bash
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umount /mnt/snapshots
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```
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## Recovery
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**Mount a Subvolume with Recovery Options**
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```bash
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mount -o recovery,subvol=backups UUID=aa5c1d34-ecba-42a9-9339-8f7879d47536 /mnt/tmp
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```
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**Clear Cache During Mount**
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```bash
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mount -o clear_cache,subvol=backups UUID=aa5c1d34-ecba-42a9-9339-8f7879d47536 /mnt/tmp
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```
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**Data Restoration**
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To restore data using `btrfs restore`:
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```bash
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btrfs restore -D /dev/sdb
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```
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## Drive Manipulation
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**Mount Whole Drive**
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```bash
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mount UUID=c9a77f3c-626f-47bd-b4e3-9a094bea287f /mnt/tmp
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```
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**Mount Subvolume by ID**
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```bash
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btrfs subvol list /
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mount -o subvolid=5 /dev/disk/by-uuid/7a22514b-594a-43a3-8fdd-4df1530b5465 /mnt
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```
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**Add a New Drive**
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To add a new drive to an existing BTRFS setup:
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```bash
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btrfs device add /dev/sdf /mnt/media/
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```
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**Resize Filesystem**
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```bash
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btrfs filesystem resize 1:max /mnt/media/
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```
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**Create Subvolumes**
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```bash
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btrfs subvol create /mnt/tmp/root
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btrfs subvol create /mnt/tmp/snapshots
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```
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### Replace Drives
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**Replace the source drive with the target drive:**
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This command will start the replacement process where the data from the old drive (`/dev/sdb`) is copied over to the new drive (`/dev/sdj`).
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```bash
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btrfs replace start /dev/sdb /dev/sdj /mnt/media
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```
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- `/dev/sdb`: Source drive to be replaced.
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- `/dev/sdj`: Target drive to replace the source drive.
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- `/mnt/media`: Mount point of the BTRFS filesystem.
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**Monitor the progress of the replacement:**
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Once the replacement process has started, you can monitor its progress with the following command:
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```bash
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btrfs replace status /mnt/media
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```
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- This will print the current status of the drive replacement operation, showing how much data has been migrated.
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**Monitor progress interactively:**
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For a more detailed, interactive status view of the replacement process, use the `-i` option:
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```bash
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btrfs replace status -i /mnt/media
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```
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- `-i`: This flag provides an interactive mode where the progress is updated in real time.
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**Notes:**
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- The `btrfs replace` command allows you to replace a faulty or underperforming drive without unmounting the filesystem, making it ideal for live systems.
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- It can be used for upgrading storage by replacing smaller drives with larger ones, or for replacing failing drives.
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- Ensure that the target drive has enough space to accommodate the data from the source drive.
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## Balances
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**Perform a Full Balance with Minimal Usage**
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```bash
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btrfs balance start --full-balance -dusage=0 -musage=0 /mnt/media/
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```
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- `--full-balance` is default but with a warning if not specified.
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- `-dusage=0` means only data block groups that are nearly empty (0% full) will be balanced.
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- `-musage=0` means only metadata block groups that are nearly empty (0% full) will be balanced.
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**Perform a Full Balance on Partially Used Blocks**
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```bash
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btrfs balance start --full-balance -dusage=50 -musage=50 /mnt/media/
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```
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- `-dusage=50` means data block groups that are less than 50% full will be included in the balance process.
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- `-musage=50` means metadata block groups that are less than 50% full will also be balanced.
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**Balance data in the background**
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```bash
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btrfs balance start --bg -d /mnt/media
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```
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**Balance metadata in the background**
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```bash
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btrfs balance start --bg -m /mnt/media
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```
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**Balance data and metadata in the background**
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```bash
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btrfs balance start --bg --full-balance -dusage=0 -musage=0 /mnt/media/
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```
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**To balance 100 chunks of data**
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```bash
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btrfs balance start --bg -dlimit=100 /mnt/media/
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```
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**Cancel Balance Operation**
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```bash
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btrfs balance cancel /mnt/media/
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```
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**Monitor Balance Status**
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```bash
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btrfs balance status /mnt/media/
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```
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## Scrub
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**Start a Scrub Operation**
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To start a scrub operation to verify data integrity:
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```bash
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btrfs scrub start /mnt/media/
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```
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**Check Scrub Status**
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To check the progress and status of the ongoing scrub:
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```bash
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btrfs scrub status /mnt/media/
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```
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**Cancel a Scrub Operation**
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```bash
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btrfs scrub cancel /mnt/media/
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```
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## Snapshots
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**Create Snapshots**
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1. **Mount snapshot subvolume**
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```bash
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mount UUID=c9a77f3c-626f-47bd-b4e3-9a094bea287f -o subvol=snapshots /mnt/snapshots
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```
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2. **Create a new snapshot**
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```bash
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btrfs subvolume snapshot / "/mnt/snapshots/root/2021-06-26 - Debian install"
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```
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3. **Unmount after creating snapshots**
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```bash
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umount /mnt/snapshots
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```
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**Delete Snapshots**
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1. **Mount subvolume containing snapshots**
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```bash
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mount -o subvol=snapshots /dev/disk/by-uuid/7a22514b-594a-43a3-8fdd-4df1530b5465 /mnt/snapshots/
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```
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2. **List available snapshots**
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```bash
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btrfs subvol list /mnt/snapshots/
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```
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3. **Delete the desired snapshot**
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```bash
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btrfs subvolume delete /mnt/snapshots/@rootfs/2024-09-15
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```
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4. **Unmount after deleting snapshots**
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```bash
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umount /mnt/snapshots/
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```
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