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user1
July 28th, 2007, 08:53 AM
I reallize that the newer amanda server can be started with TCP or UDP. I also notice that the installer by default sets up the server and the client to listen to TCP, with stream protocol. Is this the preferred way future installations should be carried out? All the vintage instructions tell you to use UDP, open up UDP ports etc. I've got amcheck working and realize I have to choose the scheme consistenly on the server and client.

Can somebody explain the difference -- any performance, security, or capability implications?
What is the preferred scheme?
What is the deal with auth=bsdtcp, bsdudp and bsd? How does it relate to the protocol stream and dgram? Again the installer defaults to bsdtcp

Marc_Muehlfeld
July 29th, 2007, 12:35 PM
Can somebody explain the difference -- any performance, security, or capability implications?


Long information about the difference tcp/udp:
http://en.wikipedia.org/wiki/Transmission_Control_Protocol
http://en.wikipedia.org/wiki/User_Datagram_Protocol

In short words: If you send tcp package, the receiver will send a package back to confirm. On udp you don't get that confirmation. So normally important information is transported over tcp and data where it's not a problem to loose a package (e.g. video transmission) is send via udp protocol.





What is the deal with auth=bsdtcp, bsdudp and bsd? How does it relate to the protocol stream and dgram? Again the installer defaults to bsdtcp


http://wiki.zmanda.com/index.php/Server/Client_authentication

user1
July 29th, 2007, 04:53 PM
Long information about the difference tcp/udp:
In short words: If you send tcp package, the receiver will send a package back to confirm. On udp you don't get that confirmation. So normally important information is transported over tcp and data where it's not a problem to loose a package (e.g. video transmission) is send via udp protocol.


So the answer is : TCP consumes network bandwidth due to the confirmation package. It will be compromising your backup strategy (defies the purpose of backup) if you use UDP. Based on this knowledge, my recommendation is to use TCP for amanda for your own network -- it is good tradeoff of network performance for added data integrity. Especially if you schedule your backup for nights (low traffic hours), the performance degradation of the network shouldn't be noticeable.