SDLT 600 only sees half the tape

[Philip Evelyn]

I have to SLDT 600's which, at just over 300GB's, stop the backup and tell me to insert another backup tape.

Any idea what the problem is? (yes they are 600GB tapes).

Both using Veritas 11 and both on W2K3 servers.

[Torsten.]

Hi,

see this:
http://h18006.www1.hp.com/products/storageworks/sdlt600/index.html

This drive has 300 GB native capacity - 600GB assumes a 2:1 compression. If the drive cannot compress the data (for example binary or jpeg files) the tape is full after 300GB stored.

The only problem here is to understand the marketing value of 600GB.

[Philip Evelyn]

Oh cr*****. Absolutely not the answer I wanted but thanks for the speedy reply.

Now time to go thump a salesman.

[Torsten.]

Have a look at this also:

http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=lpg50030&locale=en_US&docId=75327

"...
One of the problems with this terminology is that the storage industry adopted a "standard" compression rate of 2:1, which is used in product names and specifications sometimes causing confusion. ..."

[Udo de Boer]

Could be that the tapedrive is getting the data too slow. When the incoming datarate is too slow it first stops compressing and when that brings no help it stops the tape.

[Philip Evelyn]

Sadly it appears that as the drive is really only 300GB and has been "compressing" the data, I am never going to get my 600GB's worth... particularly as this is mostly tiff's from a DIP server.