Linux workstation starts doing the backup twice

So if you do not want it to retry again on failure set client retries for the group to zero.

How can I make sure that the backup sucessfuly done?

When I check the indexs it shows there the date of the backup,
Yes, I stopped the the second time backup manually.

Message was edited by:
Jihad Al-Jarady

Do not get confused between index and saveset backups - your index backups will run after the saveset backups regardless as to whether or not the saveset backup was successful. Index backups come from the backup server so tend to have less reasons for failure and thus more chance of success. Savesets come from a client which may be subject to issues that only affect that client - network issues, DNS errors etc.

My question now is:
How can I make sure that the backup sucessfuly done?

The easiest way like Hrvoje says is to look at the groups tab and check everything is showing green there - this is not a cut and dried guarantee that everything is backed up, but it does show that Networker has done what you have told it to.