Bcachefs interest. Good or not for my use case ? documentation ?

[Marcel Brouillet <marcel@brouillet.org>]

Hello,

I'm trying this email list, and I hope this isn't considered rude 
posting here.

==> I am interested in Bcachefs for personal use. I have found (and 
sponsor) the Patreon page. I am having a hard time understanding if this 
is for me, or if I should stick with FS types that are shipped with 
Ubuntu. It's hard to understand what all it's features are and if they 
are adequate for my usage.

The documentation that I found so far is https://bcachefs.org/ and 
https://www.patreon.com/bcachefs but it's not easy for me to grasp the 
benefits over the hassle of experimental.

==>_My usage is : for personal use, build a raid storage space for all 
my media (pictures, sound) and files (administration, legal, scans), on 
the following hardware:

- two 5Tb 2.5" HDD Sata
- one 1Tb SSD
- some external USB3 5Tb HDD and/or cloud storage (I plan on using rsync 
or similar, possibly storing md5sum of each file in xattr)

==> My understanding is that using Bcachefs

  *

    + I become one additional tester of the software. Do you need that?

  *

    + I can dedicate a partition of the SSD to cache R/W to the HDD
    RAID. Will I see the difference for 5Mb pictures rarely accessed (at
    CPU-timescale)? I'm not running a high I/O server, it's for desktop use…

  *

    - It will be a pain for me to compile it in the kernel. I'm running
    vanilla Ubuntu. I found this :
    https://www.rwardrup.com/bcachefs-on-ubuntu-20-04/. I noticed
    automount doesn't work.

  *

    - physical storage format is not finalized. Is there a risk I loose
    everything, do I need to compile updates regularly? what happens
    when physical format changes?…

  *

    - if anything goes wrong, I can't just plug the HDDs on another system.

  *

    - isn't there a strain of the SSD that, at some point, will kill it?
    If it dies, and my system is on it (on an ext4 partition) I loose
    access to my data until I rebuild a system with Bcachefs kernel support.

  *

    - would it make sense to have the external HDD be part of the RAID,
    so to automate syncing on the backup drive ?


I'm also fine with vanilla ext4 with software Raid-1 and rsync. What 
would you recommend ? Irrespective of me using it or not, I like to 
continue sponsoring the development, with my modest income.


Best,

Marcel (Paris, France)