StoreEver Tape Storage
cancel
Showing results for 
Search instead for 
Did you mean: 

LTO-ULTRIUM 2 tape real capacity with compression

SOLVED
Go to solution
Francis_15
Occasional Contributor

LTO-ULTRIUM 2 tape real capacity with compression

Hi,

I have been making probes with a cartridge hp ultrium 400GB* (* assuming 2:1 compression).
After some sessions with Data Protector a single cartridge storaged more than 600 Gbytes!!! Does anybody know what is the real capacity? How can I see the real capacity and real usage in Data Protector?
3 REPLIES
Leif Halvarsson_2
Honored Contributor
Solution

Re: LTO-ULTRIUM 2 tape real capacity with compression

Hi,
Compression ratio is hightly data dependant, 3-1 ratio is not uncommon. I have seen everything from no compression at all (if data is already compressed) to 10-1 or more (log files and empty database files).

As far as I know there is no way to check the "real" tape usage (how many feets of the media actually used).
Marino Meloni_1
Honored Contributor

Re: LTO-ULTRIUM 2 tape real capacity with compression

the real capacity of a 200/400 GB cartridge is 200 GB as native, this means that you have 200 Giga of Byte where you can write 1 or 0, the density of bits/bytes written on the media do not change with the compression enable.
the compression is based on mathematical compression algorithms that are impremented in the hardware and will remove redundancy from data by encoding patterns of input data. Thew more repeat pattern in the data, the more the data can be compresed. So the amount of data compression will vary depending of the characteristics of your data.
Francis_15
Occasional Contributor

Re: LTO-ULTRIUM 2 tape real capacity with compression

Leif and Marino:
Thanks for your help.