cancel
Showing results for 
Search instead for 
Did you mean: 

any question about full/differential and deduplicated backups

ticket
Level 2

Hi,

 

we use a server 2008r2 with backup exec 15.

Our plan is one full backup in the month and every day a differential backup on the deduplicated storage.

1)Is it possible to make a new full backup from the older full and the newest differential backup?

2) can i copy this new fullbackup to a tape? Or i must make a new fullbackup to a tape?

 

thank you for your help

best

 

8 REPLIES 8

pkh
Moderator
Moderator
   VIP    Certified
1) No. 2) No. You need to take another full backup. If you backup to the dedup folder, you can duplicate the full backup to tape

MIXIT
Level 6
Partner Accredited

What is the reasoning behind doing only one full backup per month?  That seems like a really risky way to do things. 

MIXIT
Level 6
Partner Accredited

I apologize for not directly addressing your questions but I have a question of my own:  why are you only doing one full backup per month?  If you discover a problem during a restore of the original backup file/media, you can lose up to a month worth of data.  That's a recipe for going out of business along with job loss.  Personally I do allow for full daily backups (to tape though), so is it that you're doing it to disk as the main means of backup?  If so are you not taking any data offsite? 

ticket
Level 2

Hi,

 

thank you for your answer.

1) i think you didn't understand me. I have a full backup and a differential backup is it possible to make with this backups a new full backup?

2) my full backup time need 12 hours(7tb) and i have another 30 machines to backup.

 

what do you mean with i lose data? i have 1 full backup(per month) and every day a differential from this full backup.

 

thank you

 

Colin_Weaver
Moderator
Moderator
Employee Accredited Certified

1) You can use synthetic backups to assemble a new full form a previous full and an incremental - BUT if your target is deduplication there is usually no need as the point in time restore view to all intents and purposes will sort a single full restore out for you. Note: even for tape it will sort it out but as tapes are slower and may not all be online this will be a longer, but still automated process. Also in some instances we have seen Synthetic (Incremental) backups take longer than a full for the same data (due to the total file count and not the total byte count.) This option also needs sn ESO license)

2) if you do use Synthetic backups then you can duplicate them to tape after the each sythetic full has been created (which is a secondary process that runs after the synthetic enabled incremental has finished)

 

Note: I am not sure if we offer a synthetic function for differentials (I suspect not as incremental resets the status of files known to be backed up to last backup, differentials maintain the state to last full but this information relates to the state of the source server and it will not be aware that  a full has been assembled by another method on the backup server in the meantime) You may be able to confirm this from the admin guide.

pkh
Moderator
Moderator
   VIP    Certified
You can't do synthetic backups with differential backups If you want to do synthetic backups with a dedup folder, then only the full backup can be in the dedup folder. The incremental backups must be on disk, not in the dedup folder

MIXIT
Level 6
Partner Accredited

Ticket: Sorry for the double-post, this goofy Veritas website seems to have random glitches (the day I was posting, I got http 500 errors on every post/reply I did).  They all seem to have posted nonetheless :|

 

All I was referring to was that if there was an issue of any kind with your original Full Backup then it wouldn't matter how many differentials were made, you'd be unable to restore.  I guess I'm not really sure what kinds of issues you might encounter, just that if anything whatsoever caused your Full Backup to be corrupt, or inaccessible somehow, then you'd be out of luck and your only restore option would be to go a full month previous, which for many businesses means disaster.  I don't know of any org that would cope with losing a month's worth of data hence my sensationalist comment about going out of business and all that :)

 

But 7TB, 12 hours, in that case I guess it depends on your org's work schedule but if there is any way to shorten that to even one Full per weekend I think you'd reduce risk much more.  . 

MIXIT
Level 6
Partner Accredited

Oh and one thing I should mention:  I have no experience having to work with tech support to recreate corrupted data backups or do data recovery from media or anyhthing, so maybe there are options available in that regard, my comments were just on the basic principle that incremental and differntials always require that Full to be clean and healthy for you to restor eanything.