Backup Integrity?

[brandonn]

I am getting asked some questions along the lines of "How can I trust the data that I restore is the data I originally backed up?"

Does Netbackup do any internal checksum's on the images or anything? Any material I can reference to make the bosses happy would be nice. Other then that, I have no answer to give them; I guess some insane genius can in fact re-write data on a tape for one reason or another... Hopefully not though.

[Andy_Welburn]

is to restore the data!

We get the same question every now & again on the forum - the only answer we can generally give is "Trust what NetBackup tells you".

There is the option to verify your backups, but this can, apparently, taken as long as the backup itself. I say "apparently" as it's not something I've actually utilised.

See the following for a previous post on a similar subject:

https://www-secure.symantec.com/connect/forums/questions-setting-verification-jobs

[brandonn]

Are you saying that if the data restores with no problems then there is no possibility that the data could have been modified in anyway?

If that is true, then that is a fine answer.

[Andy_Welburn · Accepted solution]

could be modified on the media between the backup & the restore - but then I'm not an insane genius (only one half of that applies) !!

***EDIT***

I just had to do it didn't I? Just 'Googled' the phrase "modify data on tape" & there were a couple of results - one from someone selling data encryption technology "Contrary to the views of some so-called specialist, it is not that difficult to modify data on tape and even easier to read then re-write the data so it appears to be the same tape as before."

So there obviously are "insane geniuses" out there! Maybe to be 100% sure of data integrity you need to consider encryption? Checksums included!

[brandonn]

Hmmm... well then. Time to research encryption! My initial question is how much load does encryption add to the backup environment? Feel free to answer that one if you want, while I dig through the manual :)

[Andy_Welburn]

What do you think I'll be doing? ;)

[J_H_Is_gone]

The KMS ( which is hardware encryption with LTO4 tape drives) that comes free with netbackup showed no real difference to my backups at all.  As the load is on the tape drives and not on my servers.

But you also have the option of encrypting from the client or from the media server ( those cost extra)

[Andy_Welburn]

I was just looking at a previous post that you contributed to, then came back to this one & thought I hadn't (if that makes sense!)

https://www-secure.symantec.com/connect/forums/encryption-question