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Diffstat (limited to 'doc/guix.texi')
| -rw-r--r-- | doc/guix.texi | 61 |
1 files changed, 53 insertions, 8 deletions
diff --git a/doc/guix.texi b/doc/guix.texi index 33ee81b150..bd7cb7a3da 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -25900,6 +25900,15 @@ switch to it@footnote{This action (and the related actions @code{switch-generation} and @code{roll-back}) are usable only on systems already running Guix System.}. +@quotation Note +@c The paragraph below refers to the problem discussed at +@c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>. +It is highly recommended to run @command{guix pull} once before you run +@command{guix system reconfigure} for the first time (@pxref{Invoking +guix pull}). Failing to do that you would see an older version of Guix +once @command{reconfigure} has completed. +@end quotation + This effects all the configuration specified in @var{file}: user accounts, system services, global package list, setuid programs, etc. The command starts system services specified in @var{file} that are not @@ -25918,14 +25927,27 @@ It also adds a bootloader menu entry for the new OS configuration, entries for older configurations to a submenu, allowing you to choose an older system generation at boot time should you need it. -@quotation Note -@c The paragraph below refers to the problem discussed at -@c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>. -It is highly recommended to run @command{guix pull} once before you run -@command{guix system reconfigure} for the first time (@pxref{Invoking -guix pull}). Failing to do that you would see an older version of Guix -once @command{reconfigure} has completed. -@end quotation +@cindex provenance tracking, of the operating system +Upon completion, the new system is deployed under +@file{/run/current-system}. This directory contains @dfn{provenance +meta-data}: the list of channels in use (@pxref{Channels}) and +@var{file} itself, when available. This information is useful should +you later want to inspect how this particular generation was built. + +In fact, assuming @var{file} is self-contained, you can later rebuild +generation @var{n} of your operating system with: + +@example +guix time-machine \ + -C /var/guix/profiles/system-@var{n}-link/channels.scm -- \ + system reconfigure \ + /var/guix/profiles/system-@var{n}-link/configuration.scm +@end example + +You can think of it as some sort of built-in version control! Your +system is not just a binary artifact: @emph{it carries its own source}. +@xref{Service Reference, @code{provenance-service-type}}, for more +information on provenance tracking. @item switch-generation @cindex generations @@ -26187,6 +26209,25 @@ This works as per @command{guix build} (@pxref{Invoking guix build}). Return the derivation file name of the given operating system without building anything. +@cindex provenance tracking, of the operating system +@item --save-provenance +As discussed above, @command{guix system init} and @command{guix system +reconfigure} always save provenance information @i{via} a dedicated +service (@pxref{Service Reference, @code{provenance-service-type}}). +However, other commands don't do that by default. If you wish to, say, +create a virtual machine image that contains provenance information, you +can run: + +@example +guix system vm-image --save-provenance config.scm +@end example + +That way, the resulting image will effectively ``embed its own source'' +in the form of meta-data in @file{/run/current-system}. With that +information, one can rebuild the image to make sure it really contains +what it pretends to contain; or they could use that to derive a variant +of the image. + @item --file-system-type=@var{type} @itemx -t @var{type} For the @code{disk-image} action, create a file system of the given @@ -27086,6 +27127,10 @@ channels can lead to the same system, bit-for-bit; when different meta-data and thus different store file names, which makes comparison less trivial. @end quotation + +This service is automatically added to your operating system +configuration when you use @command{guix system reconfigure} or +@command{guix system init}. @end defvr @node Shepherd Services |