Finally got things working.  I think the issue is a NetBackup bug. Issue VNX 2-way ndmp configuration to same media server as Isilon 3-way ndmp configuration. The restore was trying to use the tape devices attached to the VNX instead of the tape devices connected to the media server. I found no way to force the Isilon 3-way ndmp restore to use the tape devices local to the media server.  Work around: Use one media server for VNX 2-way ndmp backups and restores. Use a different media server for Isilon 3-way ndmp backups and restores.
All, I would like to get some input from the user community. I am using 3-way ndmp backup with Netbackup to backup data from my Isilon.  I was able to backup using the 256 KB record size. The problem restores FAIL using the same 256 KB record size. Has anyone else seen this problem and do you have a work around? I am currently testing.  I am hoping the issue is something in my configuration, but if this is a real bug I want the user community to know about it. Isilon version  OneFS Version 7.0.1.5 Isilon NDMP patch-106571 Netbackup  7.5.0.4
Isilon 3-way NDMP backup restore issue with NetBackup.