Hello,
Please refer the following technotes. These troubleshooting steps can be verified for restores as well.
Title:
"Unable to attach to one of the drives" error is reported while backing up remote systems
http://support.veritas.com/docs/259874
Title:
"Unable to attach to one of the drives" (a000848c HEX or e000848c HEX) is reported when a job fails
http://support.veritas.com/docs/266177
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