LTO-4 problem

[David Barlow]

I do not know if this has been discussed elsewhere but I can't find anything. I am am finding that my LTO-4 tapes appear to be consistently under length all of a sudden. They are 800GB tapes but will not take more than 600Gb of data before the tape machine spits it out and says reload a new tape. In fact the last backup I did was 530GB of R3D's according to the Finder and the request for a new tape happened after 586Gb had been written. Is this likely to be due to bad tapes (they are HP tapes) or could it mean that my tape machine is running at the wrong speed and using up the tapes too fast? I sounds the same as it always has when running and I would not say that it has been heavily used. My next worry is if the machine is running improperly, what implications does that have for being able to read data that I already have on tape?

Any advice anyone?

Thanks

David

 

[Jeff Kilgroe]

What software are you using to write the tapes? Have you updated software recently and/or changed settings?

Most of the better software out there will write redundant data to the tapes, which does occupy more space. That doesn't seem to account for the short capacities you are experiencing, though. I guess more info is needed to try and take a stab at diagnosis. Using BRU PE here and 800GB tapes usually write out at about 730~750GB after the redundancy when backing up non-compressible data like ZIP, R3D, H264, etc..

 

[David Barlow]

I am using BRU LE for OS X ; the version I have is version 2.0.0 build 56. I have not heard of a later one. This is the only software I have ever used and never had this problem before. I have always been able to save 700GB plus on a tape. The only other thing that has changed is that I am saving R3D's from Epic rather than a RED One. However, the Finder recognises that they are big files and so should still be accurate in estimating the file sizes. I use this to plan how much I attempt to put on a tape. As it is RAW video data and not very compressible, I do not expect to get more than 800GB but, as you say, less than 600 is silly. That includes the overhead, so 500Gb data! Weird.