LTO Ultrium 1 - Tape copy

[Rui Miguel Sousa]

I need help concernng one issue.
From what I've been reading the tape copy process fails if the original tape is full ( what happens a lot with some of the tapes I have...).
So what I need to know is to wich medium size shoul I format the tapes I use.......at this moment I'm formating the tapes to the default 102400.......but I think that the tape copy process will fail because the destination tape doesn't have enough free space to write the information that it is a copy (not the original tape)....

Does anyone have a clue about the correct medium size?

Thanks for your help!

[Enrico P.]

Hi,
I formatted my LTO Ultrium tape to 204800.
The max size is write on my tape.

Enrico.

[Hai Nguyen_1]

Mario,

If time allows, you should give it a try. I have never cloned a tape but I believe that if you copy using the same LTO Ultrium tape type, the clone should be successful.

Hai

[RAC_1]

Are you talking abt tape copy with OB?

If yes then the copy will have some additional data such as offsite details etc.

The crude method that we used use was using dd for it. (If you have two drives)

dd if=/dev/rmt/0m of=/dev/rmt/1m bs=10k

[Rui Miguel Sousa]

Hai Nguyen,

The problem is if the source tape is 100% full and the destination has the exact medium size after copying all the data there will be no room left to write the information on the tape telling that the destination tape is a copy not an original.....I don't know if I've expained myself very well in the first question....sorry about that!

[Rui Miguel Sousa]

Thanks Hai Nguyen,

But using HP-UX I've seen a lot of possible solution.......but what about W2K??

Can any of you help??

Thanks!

[A. Clay Stephenson]

If this is OmniBack or DataProtector, it doesn't matter what size you specify because the entire tape is going to be used - the number you enter is just used for initial Media Pool size values.

You need to make an entry in the .omnirc file of each host that has a media agent.

My "rule of thumb" is about 0.5-0.6% of nominal capacity. The padding is specified in units of medium block size so for 64k blocks OB2BLKPADDING_13=8000 (to 9600); for 128K blocks OB2BLKPADDING_13=4000 (to 4800); and for 256k blocks 2000 to 2400 should be about right.

The idea is somewhere between 0.5% to 0.6% of 200GB. I would err on the side of too much rather than too little for media copies. If you want to be extra generous then 1% will certainly cover any manufacturing differences between tapes - at the expense of long mediainits - but in practice about half that is adequate.

The downside is that this applies to the original media so it will have no effect until you re-initiaze any media that you wish to copy.

[Rui Miguel Sousa]

Sorry Anil,

The previous post was meant for you!
:)

[Hai Nguyen_1]

Mario,

The simple solution is to label the cloned tape as a duplicate of the original.

Hai