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.

       generations can be a one of the following:

       •  <number>...

          A list of generation numbers, each one a separate command-line argument.

          Delete  exactly  the  profile  generations  given  by  their  generation number.  Deleting the current
          generation is not allowed.

       •  The special value old

          Delete all generations except the current one.

                 WARNING

                 Older and newer generations will be deleted by this operation.

                 One might expect this to just delete older generations than the curent one, but  that  is  only
                 true  if  the  current  generation is also the latest.  Because one can roll back to a previous
                 generation, it is possible to have generations newer than the current one.  They will  also  be
                 deleted.

       •  <number>d

          The last number days

          Example: 30d

          Delete  all  generations  created more than number days ago, except the most recent one of them.  This
          allows rolling back to generations that were available within the specified period.

       •  +<number>

          The last number generations up to the present

          Example: +5

          Keep the last number generations, along with any newer than current.

       Periodically deleting old generations is important to make garbage collection effective.  The is  because
       profiles  are  also  garbage  collection roots — any store object reachable from a profile is "alive" and
       ineligible for deletion.

       {{#include ./opt-common.md}}

       {{#include ../opt-common.md}}

       {{#include ./env-common.md}}

       {{#include ../env-common.md}}

Examples

   Delete explicit generation numbers
       $ nix-env --delete-generations 3 4 8

       Delete the generations numbered 3, 4, and 8, so long as the current  active  generation  is  not  any  of
       those.

   Keep most-recent by count (number of generations)
       $ nix-env --delete-generations +5

       Suppose 30 is the current generation, and we currently have generations numbered 20 through 32.

       Then  this  command will delete generations 20 through 25 (<= 30 - 5), and keep generations 26 through 31
       (> 30 - 5).

   Keep most-recent by time (number of days)
       $ nix-env --delete-generations 30d

       This command will delete all generations older than 30 days, except for the generation that was active 30
       days ago (if it currently exists).

   Delete all older
       $ nix-env --profile other_profile --delete-generations old

                                                                                 nix-env --delete-generations(1)