I had installed DFSR (DFS replication) on two servers, but recently noticed that there is a separate RDC (Remote Differential Compression) feature in Server Manager, which was not installed.
DFSR documentation talks about RDC a lot, but it's not clear if the separate feature is installed as part of the DFSR role, if you had to install the separate feature to make this work.
I've googled RDC and DFSR to see if these are unrelated or not but could not find a definitive answer. Can anyone say if you need to install the RDC feature or not?
You don't need to install RDC to get DFS-R to work. RDC can make DFS-R more efficient by sending only changed data over the wire. To use RDC, you would need to install the feature and enable the feature (on the connection tab in DFS manager, if I remember correctly). But, again, it's not necessary.
When using RDC, it could cause higher CPU usage and on occasion, create higher local disk I/O. Both are generally negligible in most situations.
You dont need to install RDC feature to use RDC compression in DFSR. Read the note on http://technet.microsoft.com/en-us/library/cc754372.aspx
http://social.technet.microsoft.com/Forums/en-US/1b1963eb-dd2a-40d6-89d5-5d726a0b1dbb/is-rdc-feature-to-be-installed-before-using-rdc-compression-in-dfsr-in-windows-2008r2