Question : Tape Backup Performance

I have a Dell Powervault 110T DLT VS160 Tape Drive which is running Veritas 10, on a Windows 2000 Server machine.  I am currently running incremental backups every night and a full backup of our servers every weekend.  I have been finding that the performance of the tape drive is not currently running at the speed at which Dell claims it can run at.  Some of these tape jobs are running up to 20 hours, and when that happens we will miss the window to insert the next tape resulting in many missed backup jobs.  

I am trying to find out what the performance should be on this current setup.  Is there a way to calculate the ACTUAL performance of tape drives when backing up data?  Is there a way to speed up the backup jobs so that they run quicker?  Is there a better way to backup this data (either better hardware, or better backup software)?  

Currently we are backing up 2 servers, which are our file server and our exchange server.  The file server mostly has small Excel and Word Documents which are being backed up.  The exchange information store is the data being backed up on the exchange server nightly.  The incremental backups run every night backing up 65 GB - 79 GB of data nightly.   These backups are taking between 10 hours and 20 hours (without data verification).  

The server that Veritas  is running on has 2 x 930 Mhz P III Processors, 512mb of RAM, Gigabit ethernet card.  The Tape drive is connected through a Ultra160 SCSI card.  

The Servers being backed up are newer machines running Quad 2.66Ghz Xeon Processors, 4 GB RAM, and RAID 5 SCSI drives.  

The network that this is running on is a FULL Gigabit network, and the servers that are being backed up are fully a gigabit as well.  


Dells Specifications are as follows:

Highlights
•      Half-height form factor provides space efficiency
•      Extension of DLT family that delivers the best value for backing up 80GB1 (native) of data at transfer rates of up to 28GB/hr (native)
•      Read compatibility with DLT1 and VS80 provides great investment protection
•      This VS160 drive is also available in the PowerVault 114T tape rack enclosure

Performance
Formatted capacity, without data compression: 80GB1 of User Data
Formatted capacity, with data compression: 160GB1 of User Data assuming 2:1 compression
Type of compression: Hardware DLZ
Effective backup rate: 8.0MB/second without data compression
Up to 16.0MB/second with data compression, 2:1 compression ratio typical
Raw data transfer rate: >8.0MB/second (includes format data, user data, post amble, etc.)

Answer : Tape Backup Performance

You are never going to get rated speed, since there is always varios types of overhead.

CHeck out PCMAG and similar to see comparisons of speed and reviews.

To test the speed, backup files tat are LOCAL to the backup Device, and see how fast it is.
Then compare with Network backup ( Preferably of the same files ).

You should be using at least 20-40 GB of data to get a good comparison.

I hope this helps !