48 lines
		
	
	
		
			1.6 KiB
		
	
	
	
		
			XML
		
	
	
	
	
	
			
		
		
	
	
			48 lines
		
	
	
		
			1.6 KiB
		
	
	
	
		
			XML
		
	
	
	
	
	
| <section xmlns="http://docbook.org/ns/docbook"
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|         xmlns:xlink="http://www.w3.org/1999/xlink"
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|         xmlns:xi="http://www.w3.org/2001/XInclude"
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|         version="5.0"
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|         xml:id="sec-rollback">
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| 
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| <title>Rolling Back Configuration Changes</title>
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| 
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| <para>After running <command>nixos-rebuild</command> to switch to a
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| new configuration, you may find that the new configuration doesn’t
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| work very well.  In that case, there are several ways to return to a
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| previous configuration.</para>
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| 
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| <para>First, the GRUB boot manager allows you to boot into any
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| previous configuration that hasn’t been garbage-collected.  These
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| configurations can be found under the GRUB submenu “NixOS - All
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| configurations”.  This is especially useful if the new configuration
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| fails to boot.  After the system has booted, you can make the selected
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| configuration the default for subsequent boots:
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| 
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| <screen>
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| $ /run/current-system/bin/switch-to-configuration boot</screen>
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| 
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| </para>
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| 
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| <para>Second, you can switch to the previous configuration in a running
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| system:
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| 
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| <screen>
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| $ nixos-rebuild switch --rollback</screen>
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| 
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| This is equivalent to running:
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| 
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| <screen>
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| $ /nix/var/nix/profiles/system-<replaceable>N</replaceable>-link/bin/switch-to-configuration switch</screen>
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| 
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| where <replaceable>N</replaceable> is the number of the NixOS system
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| configuration.  To get a list of the available configurations, do:
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| 
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| <screen>
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| $ ls -l /nix/var/nix/profiles/system-*-link
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| <replaceable>...</replaceable>
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| lrwxrwxrwx 1 root root 78 Aug 12 13:54 /nix/var/nix/profiles/system-268-link -> /nix/store/202b...-nixos-13.07pre4932_5a676e4-4be1055
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| </screen>
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| 
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| </para>
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| 
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| </section> | 
