SSl1016

[Elmer Zabala]

I have encountered a problem in autoloader SSL1016.
These are the configuration:
ML530 G2
SSL1016 with 200GB Media
Windows 2000 with Arcserve 2000
The problem is, when we try to backup the 5 servers on the network, when we reach the 133 GB of data it will ask for another media, but we have a 200 GB media, why is it asking for another media eventhough it only use 133 GB of space. What is the possible problem?

thanks,
elmer

[Kurt Beyers.]

Elmer,

The tape capacity of a LTO medium is 100 GB native and 200 GB compressed, assuming a compression ratio of 2. But the data compression of 2:1 is only a rule of fist (a generalization after many observations).

The actual compression ratio is data dependent. Suppose you've got a database space file of 1 GB with only a few records of data in it. You'll achieve a very high compression ratio on this database file as it contains a lot of redundant information. But if the same database space file is completely filled with records, the compression ratio will be around 1.

You achieve only a compression ratio of 1.33 instead of 2, so your data cannot be compressed any further.

The backup software will always use the tape until the end-of-tape is reached, so there isn't any space left on your first tape with 133 GB of data.

If you want to double-checl the compression of your LTO drive, use the LTT software to check it.

Kurt

[Elmer Zabala]

Hi!

If that is the case, there is no problem at all. Do you have any support documents ie, websites that you could recommend to further explain this?
I have use the LTT and there is no problem at all when I have diagnose the drive.

Regards,
Elmer