ALL,

 

we have an issue with LTO-3 drive performance.  

 

Our environment is set up as follows:  

*       a single master server running Solaris

*       4 Linux media servers

*       4 Windows media servers

*       ADIC i-2000 tape library with 16 LTO-3 drives that are shared on a
SAN to all of the media servers with SSO

*       five NetApp VTL's that have multiple virtual libraries on each one.
Each media server is connected to two virtual libraries (also over the SAN)

 

We do all of our backups to the VTL's and are using Vault to make duplicate
copies to the physical tapes.  We are multiplexing to the VTL's and then
de-multiplexing to the physical tapes.

 

We are currently seeing only about 11MB/sec going out to the physical tapes.
However, our read performance on the dups is averaging about 80 - 100+
MB/sec from the VTL's.

 

Is anyone else doing something like this and are you getting better
throughput to your physical tapes using Vault?

 

Symantec told us today that doing a single-stream to the physical LTO-3
drives was only going to do about 8 or 9MB/sec and we should "Preserve
Multiplexing" for the output in order to get better throughput to the
physical tapes.

 

Does this sound right?  It's sounding kind of fishy to me.   We have our
buffers set as follows:

 

NUMBER_DATA_BUFFERS:   128

 

SIZE_DATA_BUFFERS:  262144

 

 

 

thanks......

 

--stuart

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