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           Snapshots
Snapshots
       
     
    
  
	  
     
      ... trying to explain snapshots ...
      
       
      Snapshots are a very nice feature - but handling them is not very intuitive.
        This is partly because the terminology that VMware uses in the manuals 
        is not a very lucky choice - and partly because nowadays the snapshot-feature 
        offers more options than previous versions.
        
        This page is a trial to explain snapshots in non-technical terms.
        It is work in progress - if you have any ideas that would help to make 
        this little guide easier to understand - please 
        let me know.
      
      
       
	
	
   
      
      ... before you create any snapshots ...
      
      
        It's monday morning - you have installed your new system and now want 
        to start work.
      
       
 
        For this example I used a little DOS-VM and created a directory "basedisk" 
        - in the VM directory you will find a vmdk-file.
        
         
 
        
        Snapshot-manager will show the current state as
        
         
 
    
 
	   
     
      ... take first snapshot ...
      
		
        
       
      
        You create a snapshot "monday" and start to write into the empty 
        box which appears as a REDO-log in the VM directory.
        For this example we create a directory named "monday" which 
        contains all the work of the day.
        
        
        
         
 
      
    
 
	  
     
      ... take second snapshot ...
       
      It's tuesday morning and you create a new snapshot "tuesday" 
        
        
         
 
      
     
	  
     
      ... take third snapshot ...
       
      It's wednesday morning and you create a new snapshot "wednesday"
        
        
         
 
      
     
	   
     
      ... take fourth snapshot ...
       
      It's thursday morning and you create a new snapshot "thursday" 
        
         
 
        
         
 
      
     
	   
     
      ... take fifth snapshot ...
       
      It's friday morning and you create a new snapshot "friday" 
        
        
        
         
 
        
         
     
	 
      Friday evening you review the work of the week: 
      
       
      You have filled a basedisk and have 5 snapshots filled with the work 
        of each single day. 
         
 
        
        The DOS-disk now looks like this:
        
         
 
      
       
     
     
      You think your work was good ...
      
       
      Deleting snapshots "friday", "thursday", "wednesday", 
        "tuesday" and "monday" one after another will merge 
        the current state of the VM into the basedisk and will delete all files 
        that were used by the snapshots. 
        
        
        The DOS-disk will look like this:
        
        
        
        The result of this action looks like this in theSnapshot-manager:
         
 
      
       
	   
     
      You think your daily work was wasted ...
      
       
      Revert to snapshot will discard fridays work.
        You can acchieve the same result by useing the action GO 
        to snapshot "friday"  - 
        in both cases you will travel back in time to the state you had on friday 
        morning, - before creating the snapshot "friday"
        
        
        The DOS-disk will look like this:
        
        
        
        The result of this action looks like this in theSnapshot-manager:
        
         
 
      
       
	   
     
      You think the whole week was wasted ...
      
       
      GOTO snapshot "monday" goes back 
        to the state of monday morning - this will only discard any changes that 
        you have made after creating the snapshot "friday" 
        
        
        
        The DOS-disk will look like this:
        
        
        
        Current state appears in Snapshot-manager like this:
        
         
 
        
        Have a look at the Snapshot-manager - it still lists the snapshots "monday" 
        - "friday" - this means that although you have gone back to 
        early monday morning you can still restore the work from
        monday - by useing the action GO to snapshot "tuesday"
        tuesday - by useing the action GO to snapshot "wednesday"
      wednesday - by useing the action GO to snapshot "thursday"
      thursday - by useing the action GO to snapshot "friday"
        
      
       
	  
	   
     
      ... to be continued ...
      
       
      ... need to add more scenarios ....
      
       
   
     © Ulli Hankeln - mail to webmaster at sanbarrow dot 
      com 
    