Duplicate job vs incremntals and their dependency to the full

[jean-francois3]

Hi all,

First time I use those forum services. I hope I'm at the good place ! ;)

So here's the thing. I have this costumer where I duplicate every single jobs to an iSCSI drive which is provided by his ISP. A free out site solution in case of fire.... So each fulls is duplicated as well as the incrementals...

Once I've finished to setup this backup solution, a question came to my mind: "If we lost everything but those backup made on this iSCSI drive, when it will come the time to restore from the incrementals, Will the incrementals reconise the duplicated full as "the full" to refer to ? or it will look for the original full ?

I think it's gonna refer to the original but i'd like to have a confirmation.

Thanks !!!

[Nasharat_Maner]

Hi,

The duplicate incrementals will refer to duplicate Full and not the original Full. You are good in case of disaster. Using these duplicated sets, you can restore the data successfully.

[pkh]

How does the duplicated incrementals know that there is a duplicated full backup?  What happens when the user chooses not to duplicate the full backup for some reason.

[Nasharat_Maner]

Duplicate job has different family GUID than that of Original job. When it tries to restore data from Duplicated Incremental, it will refer to the Full which has same family guid as of duplicated incrmental (in this case duplicate Full) and restore data from the same.

[pkh]

What happens when the user chooses not to duplicate the full backup?  Will the duplicated incrementals automatically use the original full backup?  If yes, how does the duplicated incremental backups know the GUID of the original backup family?

[jean-francois3]

Many thanks for those explanations Nasharat !

[Colin_Weaver]

From what I remember whilst testing other things in 2012 if you have  duplicate set and the original set both available on a 2012 server and do a restore, the restore wizard presents you with radio buttons for every set that appears in both locations and as far as I am aware you can select a full form the original, the 1st incremental form the duplciate, the second incremental from the original etc and it will still work (for standard remote agent backups with disk to disk duplication and possibly where the original catalog files still exist)

The OP might be able to test the above if they already have sets in both locations if true however it should mean BE can handle re-assembly if the sequcnce is split acorss the original and duplicate devices

I am not sure it still works with GRT enabled sets (Exchange, VMware etc) or when the duplicate is on tape with original on disk.

[pkh]

You are correct in that you can manually choose from either the original or the duplicate family to do your restore.  However, with the smart restore of BE 2012, if you choose an incremental backup from the duplicated family to restore, will BE 2012 be able to automatically choose appropriate backup sets from the duplicated family?.  Nasharat says yes which leads to my question: What happens when the full backup is not duplicated?  Will BE 2012 be able to automatically use the original full backup if a duplicated incremental backup is chosen for restore?