HP MSL2024 robotic library with 2 drives

I trust you have a Library Expansion Option license for the 2nd drive, otherwise Backup Exec won't use it. The media server license contains a license for the first drive in an autoloader/library, but then every drive after that needs that LEO license.

make sure you haven't connected it to a RAID controller, and that the SAS card supports tape automation. The rest is easy. Plug into the SAS controller on the server, start up the library and scan for hardware changes.

Once done, run tapeinst.exe to install the Symantec drivers; load the LEO license in Backup Exec; and then make sure the robotics show up as Unknown Medium Changer within Windows Device Manager.

Point your jobs to the library and let BE do the rest.

And I assume you mean BE 2012, not 12.1?

Thanks!

I have one SAS Cable with daissy chain one end .

I don't recall ever seeing a SAS cable that daisy chained, so that might need investigation.  There are SAS fan out cables, such as http://www.pc-pitstop.com/sas_cables_adapters/F8888X4-1M.asp

Since you have two tape drives, you need to make two connections between them and the BE server. 

So you need either:

2 SAS ports on the server with 2 simple cables

OR

1 SAS port on the server with a fan out cable.

The fan out cables typically have 4 ends.  Just ignore (for future use) the two ends that you don't need now.