The vserver project is dead. The last kernels it supported were 3.14 and 3.18, and even those were considered experimental. In fact, the last kernel for which vserver's upstream labelled their patchset as "stable" was 2.6.22.
One of servers I deal with still uses vserver (despite my insistence to finally migrate it to lxc), but there's no way I'd waste any more time for any improvements. Thus, I don't see any point in you adding support for vserver in Buster. Meow! -- ⢀⣴⠾⠻⢶⣦⠀ ⣾⠁⢰⠒⠀⣿⡁ James Damore is a hero. Even mild criticism of bigots these days ⢿⡄⠘⠷⠚⠋⠀ comes at great personal risk. ⠈⠳⣄⠀⠀⠀⠀
