NAS / OpenMediaVault

[pfeerick]

So, may I know how to check whether the command did what it suppose to do.

If you didn't get any output at all, try running it again with the -v (as in verbose) flag. Add more v's (i.e. -vvv) for more verbose output. You can also add -n (or --dry-run) if you want to do so without the risk of any data being lost. I can't remember if with rclone you need to add a trailing slash to one of the paths to address it properly - probably the destination, if you want the "testing" folder inside "iz".

2. Problem accessing the sda1

I'm not sure what you're trying to say the problem is here... "/srv/dev-disk-by-label-DATA" is correct for OMV. So if you do a "ls /srv/dev-disk-by-label-DATA" you should see the contents of that drive. e.g. Is the "iz" listed?