MSL6030 LTO2 Throughput

[Mike_1038]

can anyone tell me what a realistic throughput I can expect with this drive.
I'm backing up an array of servers, but the bulk of my backup is run through snapshots on the tape server itself, mostly files.
The server is running windows 2003 server and the backup software is brightstor 11.1.

[Kurt Beyers.]

Mike,

It all depends on the size of the files.

For an ordinary file system backup, a througput around 60-75 GN/h should be reached.

For a database backup (a few very large files), a throughput around 110 GB/h should be reached.

A blocksize of 256 kb seems to be the optimal value for LTO2 and LTO3 drives (if you can specify this on Brightstor).

best regards,
Kurt

[Mike_1038]

Kurt, thanks for the reply.
It seems that I'm in the ballpark with the throughput you have mentioned.

Thanks again, Mike

[Marino Meloni_1]

The throughput may be limited by a lot of factors, so the way to proceed in identifying the bottleneck is to test one part of the solution at a time.
If you install Library and Tape Tools, the diagnostic tool from HP, you will be able to isolate the problem:
Run the device perfomance test first, it will write and read data directly form the memory of the server to the LTOII. this is the first step, and check if you can reach the expected value.
Then run the system performance test, and try reading from the source of your data, this will identify if the problem is comming from the source as 90% of the time it is.
When you know where the problem is comming from, then we can discuss how to solve it

Marino

[Andrei Lica_1]

I also have a MSL6030 Ultrium2 library
I agree with Kurt : 256KB is the optimum for writing or reading from tape.
Also you have to find the optimum size for the source controller.
I've found that for many SCSI/FC controllers 64KB is the optimum, at least for RAID5.
The speed also depends on the compression ratio
I got 50MBps on MSL6030 with Ultrium2 FC attached and 105MBps on Ultrium3 SCSI attached, top speeds - using dd