Why are there repositories.old.XXXXXXXXXX folders?

Hi,

I’ve restored a GitLab CE 10.1.1 backup and upgraded it to 13.12.10.
But recently I found there are 2 repositories.old.XXXXXXXXXX folders in the server.

The “repositories.old.1641113327” is an empty folder, and the “repositories.old.1641124164” folder has most projects which also exist in the repositories folder.

The size of the “repositories.old.1641124164” folder is 177G, and the size of the “repositories” folder is 187G.

repositories.old folders 187G

My git_data_dirs in the /etc/gitlab/gitlab.rb is as follows, but it seems to only use the disk2 path to store repositories:
image

And I found some projects in the “repositories” folder just being an empty folder, but they can be found in the “repositories.old.1641124164” folder with the content/data.

Should I keep all the repositories.old.XXXXXXXXXX folders? And why there are the repositories.old.XXXXXXXXXX folders?

Many thanks,
YJ