From 8074b3307746a94b0a656a41ceed0c577d7e8133 Mon Sep 17 00:00:00 2001 From: Chris Marusich Date: Tue, 1 Nov 2016 22:48:15 -0700 Subject: system: Add 'guix system' actions: switch-generation and roll-back. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit * guix/scripts/system.scm (roll-back-system, switch-to-system-generation): new actions. (reinstall-grub): New procedure, used by switch-to-system-generation. (show-help, process-command, guix-system): Honor the new actions. * doc/guix.texi (Invoking guix system) : Add the new actions. : In the footnote, mention that the new actions also only work on GuixSD. Signed-off-by: Ludovic Courtès --- doc/guix.texi | 51 +++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 49 insertions(+), 2 deletions(-) (limited to 'doc') diff --git a/doc/guix.texi b/doc/guix.texi index 1075a7e178..b8cb01f48a 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -11155,8 +11155,9 @@ supported: @table @code @item reconfigure Build the operating system described in @var{file}, activate it, and -switch to it@footnote{This action is usable only on systems already -running GuixSD.}. +switch to it@footnote{This action (and the related actions +@code{switch-generation} and @code{roll-back}) are usable only on +systems already running GuixSD.}. This effects all the configuration specified in @var{file}: user accounts, system services, global package list, setuid programs, etc. @@ -11178,6 +11179,52 @@ guix pull}). Failing to do that you would see an older version of Guix once @command{reconfigure} has completed. @end quotation +@item switch-generation +Switch to an existing system generation. This action atomically +switches the system profile to the specified system generation. It also +rearranges the system's existing GRUB menu entries. It makes the menu +entry for the specified system generation the default, and it moves the +entries for the other generations to a submenu. The next time the +system boots, it will use the specified system generation. + +The target generation can be specified explicitly by its generation +number. For example, the following invocation would switch to system +generation 7: + +@example +guix system switch-generation 7 +@end example + +The target generation can also be specified relative to the current +generation with the form @code{+N} or @code{-N}, where @code{+3} means +``3 generations ahead of the current generation,'' and @code{-1} means +``1 generation prior to the current generation.'' When specifying a +negative value such as @code{-1}, you must precede it with @code{--} to +prevent it from being parsed as an option. For example: + +@example +guix system switch-generation -- -1 +@end example + +Currently, the effect of invoking this action is @emph{only} to switch +the system profile to an existing generation and rearrange the GRUB menu +entries. To actually start using the target system generation, you must +reboot after running this action. In the future, it will be updated to +do the same things as @command{reconfigure}, like activating and +deactivating services. + +This action will fail if the specified generation does not exist. + +@item roll-back +Switch to the preceding system generation. The next time the system +boots, it will use the preceding system generation. This is the inverse +of @command{reconfigure}, and it is exactly the same as invoking +@command{switch-generation} with an argument of @code{-1}. + +Currently, as with @command{switch-generation}, you must reboot after +running this action to actually start using the preceding system +generation. + @item build Build the derivation of the operating system, which includes all the configuration files and programs needed to boot and run the system. -- cgit v1.2.3