Ultrium 400GB tape does not go beyond 100GB capacity

[Oscar_81]

We have data protector 5.5 installed over a W2003 std, but the ultrium 2 tape recognize only 100 GB not 200 GB as its showed in the label, and as far as I know the HW compression gets until 400 GB, any idea?

Thanks,
Oscar

[Stuart Whitby]

Sounds like you need to enable compression then. Also, this will probably depend where the data is compressed as to how much you see written to tape. It may be listing as 100GB of compressed data where the amount of uncompressed data on tape is considerably higher.

Compression figures are not guaranteed. If what you're trying to back up is already highly compressed, you're not going to get much more than the native capacity onto tape.

[Scott McIntosh_2]

How did you conclude this 100GB? Backups will only write out about 100GB before tape is full is reported? You are looking at some value in some backup software interface?

If an Ultrium-2 tape in an Ultrium-2 or Ultrium-3 drive, then native capacity is 200GB.

Thanks,
Scott
HP Support

[Oscar_81]

Hi Scott,

Thanks for your quick answer, I'm sending you the screen where the DP shows the size in MB for my Ultirum 2 cartdrige.

Any idea?

Thanks
Oscar

[Kurt Beyers. · Accepted solution]

Oscar,

The size specified during the format of an LTOx tape is only used for initial statistics by DP.

Even if you specify eg a size of 1 MB or 1 TB, DP will write approximately 400 GB of compressed data on a tape (the actual compression ratio is data dependent, the ratio of 2:1 is an often used value).

The default size of a tape can be changed from 100 GB (default value for an LTO tape in DP) to 400 GB with the following entry in the 'global' options file:

MC_13=1 36 250 419430400 4

best regards,
Kurt

[Sยภเl Kย๓คг]

Hi,

What is the capacity of the drive, is it LTO-2
LTO-1 is 200/400GB(200 Normal and 400 compressed) and LTO-2 is 400/800GB. When did this problem start, is it there from teh beginning. If not what was the last change made( tape drive or DP). Normally the compression ratio said above is ccoplished by the Hardware compression feature of the drive. Check weather the H/W compression for the drive is set as enable. Try one more option to have a software compression.see the enclosed bmp file for detail.
regards,
Sunil

[Jaclyn Rothe]

LTO 3 = Ultrium 460
Native capacity 200GB, compressed capacity 400GB
Depending on the data you are backing up you might not get the full space on the tape. Some files are not compressable or do not compress alot. Try long erasing the tape and reformat the tape with your Back up software.

Drives will automatically compress data, so you NEED to make sure that your back up software has software compression off. If software compression is on then this can cause the errors you mentioned.

[Basil Vizgin]

Guys, if you cannot remember LTO-s capacity, bookmark this link and do not confuse others:)
http://www.ultrium.com/newsite/images/UltRoadmap2005.jpg

As you can see, LTO-1 is 200GB compressed (100 uncompressed), LTO-2 is 400GB compressed and this year LTO-3 is 800GB compressed capacity.
LTO-3 from HP is Ultrium 960 Tape Drive.

[Scott McIntosh_2]

It's Ultrium-1, Ultrium-2, and Ultrium-3, technically. Not LTO-1, LTO-2, or LTO-3.

Which are 100GB, 200GB, and 400GB native capacity, respectively. Only the capacity is fixed by the standard, the native speeds vary between half-height and full-height, and also between HP, IBM, and Seagate/Certance/Quantum/company-of-the-year.

Ultrium960 is named as such because [800]GB 2:1 compressed + [160]MB/s 2:1 compressed is 960. Maybe they should have done the speeds in hex, or better yet, native speed/capacity instead of these unreliable 2:1 "salesman" numbers.

[Colin Main]

I am suffering a similar problem. I have a 200/400Gb Ultrium 460 which is taking somewhere in the region of just 150-180Gb. We are copying files to the device directly from HPUX-11i, using cpio so we can be fairly confident of the amount of data going on (at least confident enough to know we are quite a bit short of the native capacity and cpio does not have that much of an overhead).

Any pointers would be most appreciated.

Many thanks,

Colin Main