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Idea for Backing up data only once

Hi,

We deal with plenty of data that does not change allot after it has been created.  However every time we run a full backup it keeps on backing up the whole lot. Incremental are a problem as they need all the previous backup and the full. If something happens to full back up or incremental you toast.

Differential keeps on backing up same files plus new since the last backup. Keeps on growing and takes longer each time. Cannot restore just from the differential as it also needs full backup. If something happens to full back up all the differential are useless.

Idea,

Can I suggest to have an option to run a full backup that will only backup new files every full back up? I.e... If the data already exists on the storage/ tape then only back up the new files.

Basically it would be a “full incremental” each run. It would also be independent when it comes to restores as I might only need a file from the last backup. Therefore don’t need to load up previous backup tapes.

Benefits,

No backup storage De-dupe required, allot less tapes and much faster backups.

Might have to use catalogues for that or change the archive marker only if the file has changed.

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6 Replies

Re: Idea for Backing up data only once

I don't think Backup Exec would support it.

You can use some tools like robocopy.

Re: Idea for Backing up data only once

There are a couple of disadvantages to your suggestion.

1) There is no easy way to identify which are the new files and which are modified files.

2) Your backup method is incomplete in that all the modified files will not be backed up.  An unsuspecting user would be left unprotected because he does not know that his modified files are not backed up.

If as you claimed, your files rarely change, then your incremental backup should contain almost all new files.  There is no need to invent a new backup method for your case.

If you are using incremental backups and want to backup a file from the latest incremental backup.  You can do so without loading the full backup or the earlier incremental backup.

Re: Idea for Backing up data only once

1) There is no easy way to identify which are the new files and which are modified files.

-Response
Does it matter, what does backup exec do now? does BE backup part of a file or a whole file?
My understending is that a file is ether marked as ready for backup or not. (Archive bit on or off)


2) Your backup method is incomplete in that all the modified files will not be backed up. An unsuspecting user would be left unprotected because he does not know that his modified files are not backed up.

-Response
Same as above, changed or new file will be backed up.


If as you claimed, your files rarely change, then your incremental backup should contain almost all new files. There is no need to invent a new backup method for your case.

If you are using incremental backups and want to backup a file from the latest incremental backup. You can do so without loading the full backup or the earlier incremental backup.


-Response
For me as it stands, inceremental is a maga risk. It takes one incremental not to work for some reason and the rest of your incrementals after that are not good.
Plus, how many daily incrementals should there be before making another full backup. its ok if you have few TB not hundred's of TB.

What I'm proposing is; that each Full Incremental is effectivly a full backup for that week/ month that can be accessed independently. Ie.. does not require the original full backup to restore data that was created just few days ago.

Another way is to allow to restore data from incrementals without needing previous chained incrementals and a full backup, or at least needing previous incrementals.

 

Tags (1)

Re: Idea for Backing up data only once

My understending is that a file is ether marked as ready for backup or not. (Archive bit on or off)

Yes.  Both modified and new files would have their archive bit on, so it is difficult to distinguish a modified file from a new one.

Same as above, changed or new file will be backed up.

This is what an incremental backup does.

I don't understand. You have earlier proposed

Idea,

Can I suggest to have an option to run a full backup that will only backup new files every full back up? I.e... If the data already exists on the storage/ tape then only back up the new files.

Which is which? Do you want the modified files to be backed up or not?

 

As for your idea, as I said before, if your file in in a particular incremental backup, you do not need the previous incremental backup or full backup.

Your idea for a "full incremental" would result in this: Suppose you have files A, B, C in a folder, files A, B are previously backed up. File B is modified to file B1 and file C is a new file. Your next "full incremental" will only backup file C, but not file B1. How are you going to recover file B1?

If you are concerned about space requirements, then the solution for your largely unmodified files would be to use a dedup storage.

Re: Idea for Backing up data only once

Hi  pkh,

Thanks for that. I feel like i'm not quite sure I understand how the incremental works.

Does an Incremental backup full file when a file has been modified or just a part of a file? (the part that changed)

Your example with B and B1 makes me think that incremental only backs up the file difference and not a whole file. Is that correct?

Thanks in advance

 

Re: Idea for Backing up data only once

Your example with B and B1 makes me think that incremental only backs up the file difference and not a whole file. Is that correct?

No. The whole of B1 would be backed up.

However, if you use a dedup storage, then only the modified parts of B1 would be backed up.