LTO2 tapes

[DrPerceptron]

Anyone know, on a working properly setup, how long it takes to write 200GB of data to an LTO2 tape? (it's in an LTO3 drive if that makes any impact, but I think the tape is the limiter in that scenario)

 

I'm trying to work out whether or not they're writing at the speed they should be as my backups are taking 34 hours to complete... but I am backing up a LOT of data as well.

[bossman]

@DrPerceptron:

 

What is your system setup i.e. D2D2T or just directly to tape and what software backup app are you using?

[strawberry]

That does seem excessive for 200g of data

[bossman]

@DrPerceptron:

 

Using D2D2T where the Tape drive is connected via SCSI connector and the initial D2D is over Gig Ethernet this is what I get using Symantec BE12.5:

 

Differential:

Gig Ethernet D2D 80GB = 3.50hrs

SCSI D2T 80GB = 0.45hrs

 

So you can work out what 200GB would be fairly easily,

 

Hope this helps

[DrPerceptron]

That does seem excessive for 200g of data

 

probably should've have clarified that the 34hrs is for 2TB (at last check, probably more now), can't recall the time for 200GB.

 

I don't have enough physical space to D2D2T, so it's remote disk to tape.

[strawberry]

Forgive me, but as a sanity check.... An LTO tape is a maximum capacity of 200GB, Are you using a tape autoloader or changing the tapes manually?. Also the 34 hours includes the time it takes to make the backup and move it to the tape?.

 

Which software are you using?

[DrPerceptron]

The tapes are in a library, lost most of my sanity working in a school, but not that much

 

In 1hr I am copying (SCSI D2T) ~60GB to an LTO2 tape (Hardware, otherwise Software compression)

[DMcCoy]

60GB/H to LTO2 isn't too bad, assuming the data isn't very compressible. The native uncompressed capacity is only 72GB/H for half height. Are you encrypting with BE? LTO4+ has hardware encryption, whereas LTO2 doesn't. If you encrypt with BE the compression ratio will probably drop to 1:1.

 

So 60GB, assuming any encryption for LTO2 is pretty respectable.

 

However, backing up 2TB with only LTO2 is madness. LTO6 will fit it all on one tape!

[DrPerceptron]

hmm, I guess I'll have to plug on then, I guess I was expecting more just because I'm impatient.

[DMcCoy]

LTO2 is 11 years old!

[DrPerceptron]

Only a year older than the majority of our staff laptops then :/