Hi,
Please check if your device is listed compatible with Backup Exec. Refer the following technote:
http://support.veritas.com/docs/271383
If listed please install the latest device drivers.Please refer the following technote:
http://support.veritas.com/docs/273853
If the device is not listed in HCL, install OEM drivers using the following document:
http://seer.support.veritas.com/docs/253974.htm
Refer admin manual page 138 onwards for more information on configuring devices:
http://seer.support.veritas.com/docs/266190.htm
Additionally refer this technote:
http://support.veritas.com/docs/255501
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