btdu - a sampling disk usage profiler for btrfs (written in D)

[user1234]

On Monday, 9 November 2020 at 12:52:12 UTC, Vladimir Panteleev 
wrote:
> On Monday, 9 November 2020 at 12:21:55 UTC, user1234 wrote:
>> I like the report about how D was efficienet to develop this 
>> tool, otherwise
>> what do you use it for ? What is the typical usage of such 
>> tools ?
>
> Well, the README and linked blog post answer that to some 
> extent, but my personal use cases are actually tangential to D, 
> so I can write more about that here.
>
> I've been using btrfs on my home system ever since switching to 
> Linux full-time, and a few years ago I switched over the server 
> (hosting this forum / the wiki / some other services) to it 
> too. This allowed us to have incremental, atomic, hourly, 
> off-site backups, which actually saved our butts big-time when 
> the hosting provider decided to shut off the server over a 
> clerical issue in the distant year of 2019. Some snapshots are 
> also retained for a while to allow rollbacks or undelete files 
> in case I fat-finger something during maintenance.
>
> One of btrfs's boons is that across subvolumes and clones, 
> deduplication allows reusing the same unique block across many 
> files and snapshots, which saves space but also what enables 
> atomic snapshots to work (with successive writes being COW). If 
> you add compression on top of that, it can be challenging to 
> understand what is actually using how much space, and since 
> storage costs are not insignificant on a FOSS budget, it does 
> need to be managed, and I was missing a tool that would help do 
> this. Another unique benefit of btdu is that it starts 
> displaying results almost instantly, which is great when the 
> disk is full causing everything to be on fire and you need to 
> free up some disk space right now.

Allright it's clearer now, thanks for the clarifications ;)