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Diffstat (limited to 'doc/guix.texi')
| -rw-r--r-- | doc/guix.texi | 47 |
1 files changed, 43 insertions, 4 deletions
diff --git a/doc/guix.texi b/doc/guix.texi index 7715b72818..20bf28424e 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -5369,9 +5369,24 @@ information about the @code{nss-certs} package that is used here. Assuming the above snippet is stored in the @file{my-system-config.scm} file, the @command{guix system reconfigure my-system-config.scm} command instantiates that configuration, and makes it the default GRUB boot -entry (@pxref{Invoking guix system}). The normal way to change the -system's configuration is by updating this file and re-running the -@command{guix system} command. +entry (@pxref{Invoking guix system}). + +The normal way to change the system's configuration is by updating this +file and re-running @command{guix system reconfigure}. One should never +have to touch files in @command{/etc} or to run commands that modify the +system state such as @command{useradd} or @command{grub-install}. In +fact, you must avoid that since that would not only void your warranty +but also prevent you from rolling back to previous versions of your +system, should you ever need to. + +@cindex roll-back, of the operating system +Speaking of roll-back, each time you run @command{guix system +reconfigure}, a new @dfn{generation} of the system is created---without +modifying or deleting previous generations. Old system generations get +an entry in the GRUB boot menu, allowing you to boot them in case +something went wrong with the latest generation. Reassuring, no? The +@command{guix system list-generations} command lists the system +generations available on disk. At the Scheme level, the bulk of an @code{operating-system} declaration is instantiated with the following monadic procedure (@pxref{The Store @@ -7077,7 +7092,7 @@ supported: @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 GNU.}. +running GuixSD.}. This effects all the configuration specified in @var{file}: user accounts, system services, global package list, setuid programs, etc. @@ -7218,6 +7233,30 @@ KVM kernel module should be loaded, and the @file{/dev/kvm} device node must exist and be readable and writable by the user and by the daemon's build users. +Once you have built, configured, re-configured, and re-re-configured +your GuixSD installation, you may find it useful to list the operating +system generations available on disk---and that you can choose from the +GRUB boot menu: + +@table @code + +@item list-generations +List a summary of each generation of the operating system available on +disk, in a human-readable way. This is similar to the +@option{--list-generations} option of @command{guix package} +(@pxref{Invoking guix package}). + +Optionally, one can specify a pattern, with the same syntax that is used +in @command{guix package --list-generations}, to restrict the list of +generations displayed. For instance, the following command displays +generations up to 10-day old: + +@example +$ guix system list-generations 10d +@end example + +@end table + The @command{guix system} command has even more to offer! The following sub-commands allow you to visualize how your system services relate to each other: |