How to determine storage usage of each snapshot?

I’m trying to get more detail on how the storage in my repository is being used, so that as it runs out of space, I know what will be most impactful for reducing storage usage.

As far as I can tell, snapshot list tells the size of the snapshot (how much space the backed up files took up at the time they were backed up) but not how much storage the actual snapshot is using after accounting for deduplication.

Is there any way to get to the actual storage usage for each snapshot?

With many snapshots and versions for each snapshot, I’m struggling to map these to their storage usage.

Unfortunately answering the question is quite hard precisely because of deduplicaton.

kopia snapshot ls --storage-stats should print incremental size each snapshot used compared to the previous one.

jarek@jareks-mbp:/Users/jarek/Projects/Kopia/repo
  2020-11-30 23:50:01 PST kffb0c922fc26b8940fc29fa9ebecc624 566.6 KB drwxr-xr-x files:140 dirs:23 new-data:570.6 KB new-files:140 new-dirs:23 compression:0% (monthly-19,annual-3)
  2020-12-31 23:50:00 PST k788a8ec846ed45313b6cb1e82e141c8a 572.5 KB drwxr-xr-x files:140 dirs:23 new-data:403.6 KB new-files:51 new-dirs:23 compression:0% (monthly-18)
  2021-01-31 23:46:58 PST k1ff379103e7a8b413344b44007fa95ed 640.9 KB drwxr-xr-x files:151 dirs:25 new-data:501.5 KB new-files:77 new-dirs:23 compression:0% (monthly-17)
  2021-02-28 22:50:02 PST k0c8787879b81d39c72c85b82313684ab 680 KB drwxr-xr-x files:182 dirs:35 new-data:415.1 KB new-files:73 new-dirs:34 compression:0% (monthly-16)
  2021-04-30 06:12:54 PDT ke66f878a256a363f42af49dc1e4e78dd 671 KB drwxr-xr-x files:151 dirs:23 new-data:217.8 KB new-files:148 new-dirs:23 compression:0% (monthly-15)
  2021-05-31 23:54:16 PDT kbbf3a5ab1905efb7a9a704f4782b9785 720.3 KB drwxr-xr-x files:154 dirs:23 new-data:202.2 KB new-files:105 new-dirs:22 compression:0% (monthly-14)
  2021-06-30 23:52:52 PDT k9065d03d450f26835ec87d72b6bfc45b 744.7 KB drwxr-xr-x files:164 dirs:25 new-data:153.6 KB new-files:73 new-dirs:22 compression:0% (monthly-13)
  2021-11-30 22:50:00 PST k50d56093831023a1cb22e805e8238f93 860.7 KB drwxr-xr-x files:178 dirs:26 new-data:247.7 KB new-files:144 new-dirs:25 compression:0% (monthly-12,annual-2)
  2021-12-31 23:01:32 PST k2e3bd92bfeb42b909cbe28abcbdd6415 0.9 MB drwxr-xr-x files:221 dirs:39 new-data:149.2 KB new-files:84 new-dirs:37 compression:0% (monthly-11)

new-data tells you the size of data that is in new snapshot when compared to previously listed snapshots.