Tape to tape duplication - Less data size

[cs3472]

Hi all,

We performed tape to tape duplication for one of our client...

When we compared the size of the data, it was less from the original copy from where it was duplicated.

I have attached the screenshot for the reference... In the attachment the first one is the new tape to which the data was duplicated ( Around 630GB)

Note: There is no other data stored in the second tape.

Please let me know the reason.

Thanks

[revarooo · Accepted solution]

One was MPX'ed the other was not, therefore more use of blocks on the MPX'ed tape.

[cs3472]

Thanks revaroo...

But when we expired the backup id's in the second tape through GUI, the data size is still seen in the available_media command. Is it normal or is there anything else to be done to make it reusuable?

Thanks in advance...

[Marianne]

is there anything else to be done to make it reusuable?

ALL images need to expire to make a tape reusable.

See this excellent blog: https://www-secure.symantec.com/connect/blogs/understanding-how-netbackup-writes-tape

You can use 'Images on media' report (or bpimmedia from cmd) to compare images on the 2 tapes.

[revarooo]

Perfectly normal, see Mariannes post below for the explanation