If I want to backup two NDMP V3 compliant NAS disks systems (disk1 and disk2) with standard SCSI interface tape library including two tape drives (tape1 and tape2) and one robotic, should I connect:
- Whole library (tape1, tape2 and robotic) to one NAS disk to backup two NAS system, or
- One tape drive and robotic to one NAS disk, and another tape drive interface to another NAS directly, or
- Tape1 to disk1, tape2 to disk2, and robotic to DMA?
- If all configuration work, which is recommended?
- With the SCSI service PASS THROUGH function supported by NDMP (in configuration 1 and 2), do I still need "NAS and tape library compatibility (both tape and robotic)" to be certified by NAS disk vendor, or just the tape drive (within the tape library) be certified by NAS vendor?
These are tough questions without knowing all the details. I'll try to give my best guess but I highly recommend that you download the specification from http://www.ndmp.org/. That's really the final source. Since you work for a tape vendor, your solutions group would be able to help you probably much better than me.
To attempt to answer your questions:
- Doing this would work but introduces extra work (overhead) for the one NAS disk and if it's broke, you won't backup the other.
- That would only let the robot work for one tape and that's not where you want to go.
- That will probably work but you don't have much flexibility (what if one tape breaks)?
- I would actually recommend another server or network-attached tapes. There's a good white paper that you can download from http://www.atlp.com/pdf/WP00005.pdf titled "Using a network attached enterprise tape library with NDMP."
- I don't know about certifying with the NAS disk vendor. That's a vendor-to-vendor question in your case so I recommend you talk with someone from Network Appliance for example.
This was first published in August 2001