HP 12/24 DAT - Backup Exec asking for tape 2 at 10.4GB

[KBenware]

I am using Netware 5.1, and Backup Exec 8.5 on a Compaq ProLiant ML350 w/1GB Ram, and 57GB of RAID 5 volume. I have an internal HP 12/24 DAT drive using the Compaq 53C876 controller.

I currently have about 16GB in actual use on the volume.

Invariably, when I have more than 10.5 GB in use, Backup exec will ask for a second tape. This is at about the 96% done mark.

Any Ideas?

Thanks in advance.....

 

[Zelandakh]

Are you using 12GB tapes or are you using smaller tapes? 10.5GB of physical data could be taking up 12GB of space - have you got hardware comp enabled?

 

[KBenware]

Hardware Compression is enabled, and we are using the HP DDS-3 24GB DAT Carts.

On another server, I am using the same software, but with a quantum DLT 4000 (20GB /40 compressed). It asks for a second tape at the 15GB mark.

 

[Zelandakh]

Try using software compression instead. See if that helps...

 

[EricP]

We are using the same hardware (DAT24) on an HP Netserver with using Backup Exec as well. We are using the correct tapes with software compression turned on. Our backups were working fine last month with same hardware and same type of tapes. We are only backing up 16.5GB of data. What is the difference between hardware compression and software? Thanks for any help.

 

[Zelandakh]

Hardware comp is done on the HP drive itself.
Software is like pkzip to put compressed data onto the tape in a sort of archive.

 

[KBenware]

I've tried both hardware and software compression. I've also frogged around with block sizes on the tape (partition configuration). Changing the block size to 4096 got it to backup 15.6GB, but it still asks for the second tape. I can't believe that this is filling up a 24GB tape. :-(

 

[CinciTech]

FYI... When a tape is labeled 24G as in the DDS-3 that is with IDEAL compression of 2:1. This is usually not the case. As for getting less than what would be considered 1/2 the "advertised capacity" or 1:1 ratio, that is something that I have never seen myself. Are you possibly running Netware on compressed volumes?

 

[CTX]

I have a similar problem, Im backing up to a travan (yes I know!) using Veritas BU Exec 8. It was working fine untill the begining of the week where it now asks for another tape! I added up the files im backing up , they came to 10.5gb The tape has a capacity of 20gb compressed. Im running hardware compression with overwrite and Compare enabled. Yet when it fails Backup exec had estimated 17gb and processed 15gb! Why? Does anyone know why this maight be?