Increase size of sparsebundle for TimeMachine

I am using a sparsebundle store on a linux server. It worked well until tomorrow.

Today Time Machine tells me that the size of the sparsebundle (500gb) is not sufficient. So I use hdiutil command for increasing the size of the sparsebundle: hdiutil resize -size 600G xxx.sparsebundle. The command works fine but Time Machine seems to not see the increase of the size of the sparsebundle (it only sees that the size is 500gb and so it can't continue to backup).

Do you have any idea for solving this issue?

NB:

• the sparsebundle is encrypted


• Time Machine mounts automatically the sparsebundle (linux server configured with afp and netatalk).