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 The time in Wales is: 28 April 2017 22:47:43

Backup Session Tutorial

Traditional Backups

Traditionally backup programs work like this (Expand to display):

Traditional Backups

AISBackup's way

AISBackup sessions are analogous to traditional incremental backups, the differences are:

  1. AISBackup does not use the archive bit when backing up, and leaves it alone so as not to upset any other backup program you may run.
  2. When it comes to restore: AISBackup shows you all files that exist on the chosen session, as opposed to just the files that were physically backed up.

AISBackup does not do what is known as Differential backups because it makes no sense for AISBackup.

AISBackup does not use the archive bit so multiple backups of the same data may be made without upsetting any legacy backup program which uses the archive bit.

The first time a backup job is run AISBackup backs up all selected files and catalogues these files in a file called the Backup Contents File. All files are placed in Session 1 the first time a backup job is run, so put another way Session 1 contains all files that have just been backed up. This is exactly the same as a traditional full backup.

The next time the same backup job is run AISBackup compares the files on disk with the files catalogued in he previous session. Any new files and changed files are selected for backup, and the selected files are physically backed up. Any files in the previous sessions that no longer exist on the PC are marked as deleted in the current session  - this is because they were  deleted some time between the last Backup session and this backup session. For each changed file there now exists multiple entries in the catalogue, one for each session the file changed. This is best seen by creating a backup of a few text files to a local disk based backup:

  • Open Windows Explorer (Right click 'My Computer' and choose Explore), from the left hand pane expand My Computer and click C:
  • Right click in the right hand pane and choose New / Folder and rename the folder AISSess.

  • Double click the folder then right click the right hand pane and chose New / Text Document three times, the folder should look like this:

  • Create an AISBackup job, choose destination disk, and select the folder C:\AISSess as the source of the backup (New Job / Next / A Local Hard drive or Network Drive / Next / Type SessTest / Next / Next /Next / Select the folder AISSess / Next / Run / Continue). Having run the backup click Restore From Backup, choose All Sessions (the default) and click Next. The restore files selection form shows the same three files. 

  • Look at the sessions column, all three files were created in session 1 as denoted by C1, all three files physically reside in zip file 1 as denoted by Z1.

  • From Explorer double click the file New Text Document (2).txt and enter some text, then save this file.

    Create a new text file, this should be called New Text Document (4).txt.

    Right click New Text Document (3).txt then while holding the shift key down choose Delete. (shift Delete means delete and not move to recycle bin).

    The folder should now contain the unchanged file New Text Document.txt and the changed New Text Document (2).txt and a new New Text Document (4).txt. Click Cancel on the AISBackup restore files form then click Run Backup, then Continue on the comment request dialogue. Then choose Restore From Backup / All Sessions:  / Next

  • Notice that there are now 2 entries for New Text Document (2).txt one Gen(eration) 1 and the other Gen(eration) 0. Gen 1 was created in session 2 and is on zip file 2, Gen 0 is now shown as deleted in session 2, and so is New Text Document (3).txt. Double click each entry of  New Text Document (2).txt and you will see that Gen 0 has no data and Gen 1 has data. The New Text Document (4).txt file is shown as created in session 2 (C2). Now from the Restore From Session drop down combo box choose Session 2.

  • You will now only see the files that existed on the PC when session 2 was backed up. Choose Session 1 and you will only see the three zero size files that existed on the PC when session 1 was backed up, i.e. just like the first Select Files to Restore form, above.

  • Another powerful feature of AISBackup is the ability to manually or automatically prune (or remove) redundant backup data (backup data you no longer require). Cancel the restore files form and choose the menu option Manage Backup / Undo Backups (Prune Backup sessions) Check Session 1 then choose Delete and confirm with Yes.

  • Here is a snap shot of the log activity showing the prune detail:

  • You will see that  New Text Document (2).txt and  New Text Document (3).txt were physically removed from zip file 1 because they are no longer required for any backup session,  New Text Document.txt remains in zip file 1 because it is required for session 2. If you were to look at the restore files form again you will notice that all files have been marked as created in session 2, this is because session 1 no longer exists in this backup job. In a multi-session job you may choose any session for deletion, AISBackup knows which files it can physically remove.

  • To continue this tutorial create a new file or two, change the contents of files and delete a few more, switch between sessions to see the file state that existed on the PC at the time the session was backed up. What AISBackup is doing with one or two files in this tutorial it is doing with the whole contents of your PC during a normal backup.

Summary

Remember that each backup session contains all files that existed on the PC the date the session was made, no need to worry about compiling a list of files to restore from a full backup and several incremental backups (or maybe one differential backup). AISBackup always shows you a full backup view of your files - and that is what you want to restore from unless you are a masochist.

Did you know?

If you only want a full backup and the backup destination is a disk AISBackup may be set to retain 1 backup session, then the backup will only contain a full backup of 'now' even though only differences were physically backed up. This only works logically if write once media such as CD or DVD is used as AISBackup cannot physically remove data from these drives, i.e. the backup contents file will show 1 full backup but the expired backup data will still be on the write once media.

Backups can be set to automatically prune data based on business work cycles, e.g. keep the last seven days, five weeks and twelve months. Everything that expires from your chosen backup plan is automatically pruned. This keeps the backup destination disk space to a minimum while preserving the data you want.