Stacks can be used to recover details erased in a merged layer, fix a repaired layer, or recover an entire archive.

Recovering Details and Healing Damaged Layers

In the "Updating a Stack" post there was a lot about when merged layers in an archive replace their original layers the stack.

But if those layers haven't been replaced yet, they can be used to restore those details at any point in the future.

Also, if an archive becomes damaged somehow, it may now contain repaired layers. If those layers had been previously copied to the stack, those layers can be recovered simply by replacing the repaired layer(s) with equivalent layers in the stack.

Both of these tasks are accomplished in the slices window. Open the archive, and then choose Layers > Stack Slices?. (Note that the repair action automatically opens the slices window if the archive has at least one stack and the repair detected damaged/missing data in a layer.)

Select the Recover from action.



Select the slices you want to replace in the archive. It can be layers you want to "un-merge" or repaired layers.

you can also restore layers that have been deleted from the archive.

Recovering an Archive

When the disaster is a little bigger than a repaired layer or two, the entire archive can be recovered from the stack?or at least as much of the archive that has been synchronized with the stack.

Choose File > Recover From Stack? in the QRecall application.

You begin by specifying the type and location of the stack container, exactly as you did when you created the stack. (I trust you saved all of that information somewhere safe.) But instead of prompting you for the name of a new stack container, it will ask you to select an existing stack.

You will then be prompted for the name and location of the recovered archive. An empty archive will be created. It will have the same identity and will already be connected to the stack. It will also restore all of your archive's settings.

The slices window will automatically open, and the action set to "Recover from". When you created the stack, the archive had layers and the stack was empty. This time, the archive is empty and stack has layers. Select some or all of the layers to recover and click the Recover button.

WARNING:

Archives and stacks all have a unique identity code. This is assigned when the archive and stack are created and is used to make ensure the stack belongs to the archive.

If you duplicate an archive, you create a situation where there are two archive documents with the same identity. If QRecall ever detects this, it will spontaneously reassign the identity of one of the archives.

This can be an issue when recovering an archive because, if the original archive still exists (say you just want to test out this new recovery process), QRecall may spontaneously reassign it a new identity. When this happens, one of the archives will be disconnected from the stack, and it might not be the archive you want.

If you want to test the recovery process, first rename the old archive, or make sure it's off-line during your tests. In the worse case scenario, you may have to delete one of the archives, recover from the stack again, or delete the stack and start over.