Found it out (with a little help of NGS):
options ndmpd.debug
ndmpd.debug.enable on
ndmpd.debug.filter all
This creates "all" debug logs in the following location (different from ONTAP 8.0 and below): /etc/log/mlog/ndmpd.log
For those interested, these are the valid settings for the "ndmpd.debug.filter" Option (not yet officially documented):
This option controls the NDMPD modules for debug logging is to be enabled.
It can take five values : all, none, normal, backend and filter.
all : turns on debug logging for all the modules.
none : disables debug logging for all the modules. It is equivalent to ndmpd.debug.enable option being set to off.
normal : is a short cut option that enables debug logging for all the modules except verbose and io_loop.
backend : is a short cut option that enables debug logging for all the modules except verbose, io_loop, ndmps and ndmpd.
filter : is a combination of one or more modules for which debug logs needs to be enabled. Multiple module names can be combined using following operators:
- to remove the given module from the list of specified modules in the filter string. ^ to add the given module or modules to the list of modules specified in the filter string.
The possible module names and a brief description is given below:
+--------------+-------------------------------------+
| modules | description |
+--------------+-------------------------------------+
| verbose | verbose message |
| io | I/O process loop |
| io_loop | I/O process loop verbose messages |
| ndmps | NDMP service |
| ndmpp | NDMP Protocol |
| rpc | General RPC service |
| fdc_rpc | RPC to FC driver service |
| auth | Authentication |
| mover | NDMP MOVER (tape I/O) |
| data | NDMP DATA (backup/restore) |
| scsi | NDMP SCSI (robot/tape ops) |
| bkup_rpc | RPC to Backup service client |
| bkup_rpc_s | RPC to Backup service server |
| cleaner | Backup/Mover session cleaner |
| reconf | Debug configure/reconfigure |
| dblade | Dblade specific messages |
| timer | NDMP server timeout messages |
| vldb | VLDB service |
| vol | VOL OPS service |
| sv | SnapVault NDMP extension |
| common | NDMP common state |
| ext | NDMP extensions |
| sm | SnapMirror NDMP extension |
| ndmprpc | NDMP Mhost RPC server |
+--------------+-------------------------------------+
