Anyone planning on ZFS or BTRFS for file systems?

[DrYak]

@DrYak Thank you. When I tried BTRFS over the weekend, I missed the InitRD part. (When I used BTRFS years ago, I built it into the kernel, no need for an InitRD.)

Yup, the various make inird tools' magic autodetection of file systems is of no use... if there exists no BTRFS to be autodetected yet.
(We all make stupid mistakes: on my side I banged my head a bit, having completely forgotten to update the extlinux.conf)

(on the other hand switching the /boot partition from FAT32 to Ext4 (which is also compiled in by default in the current uboot) was a breeze)

I would have documented it earlier but... well... real-life and day job got in the way :-P

So, adding that part to my prior instructions, works. Now I have the ability to perform upgrades in the same partition space. I use this on my kernel command line;

Code:

rootfstype=btrfs root=/dev/mmcblk2p8 rootflags=subvol=root/20200616

When I update, I will clone "root/20200616" and create a new sub-volume. Boot off it, and then perform the updates. After I have 4 or so OS sub-volumes, I'll delete the oldest. This gives me some backout plans, and some backups of OS files.

You might be interested in playing with snapper, it is designed exactly for that and can partially automate your workflow.

I also have my own scrub/rebalance/trim script if you're interested.