NAS Backups are going to disk instead of tape

The disk destination must have enough room for the entire image backup of the NAS device. A trace of the backup will show how many bytes are being allocated by the image backup. The example below shows a trace going to the /tmp directory on a UNIX system. If the system is Windows, use a windows path such as C:\temp or another directory:

trace disable *
trace enable bf addmsg
trace begin /tmp/strace.out

<<start the NAS BACKUP and wait a few minutes>>

trace flush
trace end
trace disable *

Review the tracefile for the following statement showing the bytes allocated:
[199][bfspctrg.c][1643][CreateMarkTrgForCheck]:Checking trigger for pool NDMPDISKPOOL strPool with allocation of 22194528493568

This is an attempt to allocate approximately 20TB. The disk pool did not have this much space and the backup failed over to tape (the next storage pool)

There is insufficient space for the NAS image backup on disk and the backup fails over to the next storage pool (typically tape).