Does sector by sector backup support btrfs

[banger696]

As per title. I have just changed one of my Linux partitions to CachyOS which has defaulted to btrfs. I have a backup set to backup two Linux partitions and their boot partitions and have set to backup sector by sector. Will the btrfs partition successfully restore?

[admin]

The sector-by-sector backup method works for any file system and creates an exact image of the source drive, so btrfs partitions can be successfully restored.

[banger696]

Great thanks.

[Dude Guyman]

Will the btrfs partition successfully restore?

I've never used BTRFS, but it worked with EXT4.
Tip: Running a Trim right before the backup saves a lot on the image file size for me.

- assuming it's the same for BTRFS?

Code:

sudo fstrim -v /

[Dude Guyman]

I've never used BTRFS, but it worked with EXT4.
Tip: Running a Trim right before the backup saves a lot on the image file size for me.

Update after more experience:
1. When I made backups of my ~80 GB (9 GB used) Linux EXT4 partition on an NVME SSD, it worked fairly well and resulted in a ~2.7 GB backup image.
2. With an ~80 GB (9 GB used) Linux EXT4 partition on a mechanical HDD, it resulted in a massive 68 GB backup image. No good!

Not sure why the type of hard drive it was on made a difference, but it did. Because no TRIM on HDD so the entire space was seen as "occupied" by data? Anyway, Macrium v8.1 handles it well, Hasleo v5.*, not so much.

[admin]

You are absolutely correct. The difference is exactly due to the TRIM command and is directly related to HBS's current lack of support for the EXT4 filesystem.
On the SSD: TRIM causes the SSD to return zeros for all unused blocks. Because HBS performs a full sector-by-sector backup (as it cannot interpret EXT4 to skip empty space), it reads these zeros, which compress perfectly. This results in a small backup file.
On the Mechanical HDD: HDDs do not support TRIM. The unused space is filled with old, random data. Since HBS cannot filter this out for EXT4, it must back up this data with low compression rates, resulting in a large image file nearly the size of the entire partition.

Therefore, the issue is a combination of two factors:
1. HBS does not support the EXT4 filesystem, forcing it to back up the entire partition at the sector-by-sector mode.
2. The storage hardware's handling of unused space (SSD with TRIM vs. HDD without) dramatically affects how well that sector-level backup can be compressed.

We apologize for any inconvenience caused by the lack of EXT4 support in the current HBS version. Your observation perfectly illustrates why this limitation leads to such different results on SSDs and HDDs.