I need more than 200GB capacity on a LTO-Ultirum tape

[Mozhdeh]

Hi
I have a problem when want to format my LTO-Ultirum tapes.
Their default size is 400GB* and some of them has more than 500GB capacity (but I don't know how they were formatted). Now, when I format them with HP OpenView, their size is 200GB and I have lots of problem with this fact. What must I do to format these tapes to have 400GB capacity?
Bye the way, Hardware compression in Drive, isn't active and I don't know how to active this check box.
Sincerely,
Mozhdeh

[Neil wix · Accepted solution]

LTO tapes (assuming you don't mean LTO2 or LTO3) have a native capacity of 100GB. They are often advertised as 100/200GB indicating their native capacity and their assumed capacity at a 2:1 compression. Of course, depending on your data, you may get more or even less than that.

If you are talking about LTO2 or LTO3, their capacities are 200/400 and 400/800 respecitively.

Hardware compression is generally enabled by your backup software. Though there may be a switch or jumper on the drive that can enable/disable it.

[Mozhdeh]

thank you very much for your answer.

[Jaclyn Rothe]

As mentioned above an LTO 2 tape have a 200 native capacity and a 400 compressed cpacity.

Depending on what drive you are using you might be able to get LTO 3 tapes with 400/800 cpacity.

LTO 3 drives (Ultrium 960) are backwards compatible 2 generations... which means that it will take LTO 1: 100/200, LTO2: 200/400, LTO 3: 400/800 GB tapes.
LTO drive are ONLY backwards compatible and will take LTO 1 and LTO 2 tapes.

HP drives have an algorithm which defaults to on whent he drive is turned on... software compression is never advised as the ratio tends to be lower then hardware compression. In certain software if you make compression selections a command is sent to the HP drive to disable (turn off) the algorithm. This is detrimental to the drive and enough of this process will permanently disable the algorithm. Powercycling the drive should recover this issue. Make sure back up software compression settings are addressed before this or when the device becomes active again it will get the command from software to turn off the algorithm again.
If powercylcing the drive does not correct the algorithm to an on state, you may have to flash the firmware (to the same version if no newer version is available). Flashing firmware is recommended to reset devices or clear SCSI BUS of errors

With the algorithm on HP drives the compression ratio is set to 2:1 compression. Individual tapes will vary depending on many factors.
Here is a document on capacity/compression varience: http://support.microsoft.com/?kbid=266011

Summary:
When tapes are manufactured, the actual capacity and tolerance of each tape may vary plus or minus several or even hundreds of megabytes from its stated capacity, depending on the total stated capacity of the media. RSS is supposed to compensate for the slight differences in tape capacities by keeping a 5 percent tolerance zone of free space at the end of the tape. Under certain circumstances, RSS may fill the media master tape almost to 100 percent capacity.

To see if this is the case, look at the Free Space column under the Remote Storage Media icon. Instead of 5 percent free, there may be only a few megabytes of capacity left on the tape. Consequently, if RSM cannot find media of equal or greater capacity, RSS cannot perform the media copy operation.