# Name `nix-env --delete-generations` - delete profile generations # Synopsis `nix-env` `--delete-generations` *generations* # Description This operation deletes the specified generations of the current profile. The generations can be a list of generation numbers, the special value `old` to delete all non-current generations, a value such as `30d` to delete all generations older than the specified number of days (except for the generation that was active at that point in time), or a value such as `+5` to keep the last `5` generations ignoring any newer than current, e.g., if `30` is the current generation `+5` will delete generation `25` and all older generations. Periodically deleting old generations is important to make garbage collection effective. {{#include ./opt-common.md}} {{#include ../opt-common.md}} {{#include ./env-common.md}} {{#include ../env-common.md}} # Examples ```console $ nix-env --delete-generations 3 4 8 ``` ```console $ nix-env --delete-generations +5 ``` ```console $ nix-env --delete-generations 30d ``` ```console $ nix-env --profile other_profile --delete-generations old ```