Newbie!! Veritas 9 Asking for more tapes

[mikey306]

Newbie to all this vertias stuff so any help would be most appreciated!!
Using HP Lto1 tape drive. i am using HP LTO 1 TAPES 100gb/200gb.
scenario - currently backing up 336gig of data but it wants 3 tapes to complete the back up! am i right in thinking it can compress the data on to 2 tapes (400gb)?? This has only recently happend so i know it will back up to 2 tapes but why is it now asking for 3 when nothing has changed in terms of settings!! Help!! much appreciated!!

 

[jgeidl]

Having had similar problems I discovered that I had hardware compression turned on when the drive I had didn't support it. As soon as I switched to software compression (not hardware if availble, otherwise software) I got the compression I was expecting.

Jim

 

[SQLBill]

Review this forum, there's LOTS about this issue.

1. The compression number is only an estimate, you will never really get that.

2. When you do a backup, you are not only putting the data on the tape, you are putting header information on it also.

3. Make sure your job is not set to APPEND. If you allow append then you will need tapes more often. BE can NOT use the 'front' part of a tape when it runs out of room appending. Ex. a 10GB tape. You backup 6 GB to it one day, leaving approx 4GB. Next day you backup 6 GB. Approx 4 GB will go on the tape and then you will need a second tape. It CAN NOT use the original 6 GB of tape.

If your job is set to allow append, yes you could really need three tapes. Ex. You append 36GB to the end of tape 1, then you fill tape 2 with about 200GB, but you still have 100GB of data left so a third tape is needed.

-SQLBill

Posting advice: FAQ481-4875