Btrfs

Immutable Atomic Linux Distirbutions

Of late, I’ve been hearing a lot of (good) things about Immutable Linux Distributions, from friends, colleagues and mentors. It has been something on my plate for some time, to explore. But given the nature of the subject, it has been delayed for a while. Reasons are simple; I can only really judge this product if I use it for some time; and it has to be on my primary daily driver machine.

There surely is need for better tooling on the BTRFS File System side.

While migrating my setup from one machine to another, this is one issue I came to be aware of, only today, when my backup tool (btrbk) complained about it. Following the pointers, I see the below snippet in btrfs-subvolume manual page.

       A snapshot that was created by send/receive will be read-only, with different last change generation, read-only and with set received_uuid which identifies the subvolume on the
       filesystem that produced the stream. The usecase relies on matching data on both sides. Changing the subvolume to read-write after it has been received requires to reset the
       received_uuid. As this is a notable change and could potentially break the incremental send use case, performing it by btrfs property set requires force if that is really desired by
       user.

           Note
           The safety checks have been implemented in 5.14.2, any subvolumes previously received (with a valid received_uuid) and read-write status may exist and could still lead to
           problems with send/receive. You can use btrfs subvolume show to identify them. Flipping the flags to read-only and back to read-write will reset the received_uuid manually. There
           may exist a convenience tool in the future.

Fixing the Received UUID: flag meant running the below:

After a hiatus of 6 years, it was nice to be back with the ThinkPad. This blog post briefly touches upon my impressions with the current generation ThinkPad T14 Gen2 AMD variant.

Lenovo

It took 8 weeks to get my hands on the machine. Given the pandemic, restrictions and uncertainities, not sure if I should call it an ontime delivery. This was a CTO - Customise-to-order; so was nice to get rid of things I really didn’t care/use much. On the other side, it also meant I could save on some power. It also came comparatively cheaper overall.

I recently switched to a ThinkPad W530 laptop. It is a fairly recent machine with the following hardware config:

• Intel(R) Core(TM) i7-3720QM CPU @ 2.60GHz
• 8 GiB RAM
• nVIDIA Optimus
• Samsung SSD Drive

On the software front, I decided to take my chances. Hence: