I like to try Amanda's and Bacula's NDMP backup features, but I don't wan't to try it out on the live NAS, just yet.
Ideally would I like to find out which that suites me best, and get familiar with before trying to make a real NDMP backup from the NAS.
Question
Is it somehow possible to simulate a NDMP backup with some Linux hosts?
Or formulated in another way:
Does there exist a NDMP daemon I can install on a Linux host, so it pretends to be a NAS?
It looks like there is a similar question already on SF: Any open source backup software with NDMP support?. I assume your looking for a free solution you could readily download and run as a daemon.
You could probably also test using the Bacula Enterprise trial with NDMP plugin: http://www.baculasystems.com/products/bacula-enterprise-plugins/ndmp
Judging from your other posts you're probably using a NetApp toaster. NDMP dumping (you can dump to null if you just want to test NDMP itself) will only create a snapshot on the volume you want it to run on and then simply copy file by file to tape (or null or another filer). There's nothing special about it and you're not "touching" anything by running a NDMP dump operation on your volumes. Currently your best bet as an NDMP source is a real filer as there are no NDMP "daemons" for Linux.
There is a sourceforge project called "NDMFS" which listens on port 10000 and claims to be an NDMP server. Unfortunately my NetApp causes it to error out with "NDMP_NOT_SUPPORTED_ERR." My guess is that it doesn't support NDMP v4 or something like that, but it might be worth trying.