I ran into the same issue with the make install portion as above.

The message reporting that the group:backup did not exist seemed to be the first of the cascade of errors.

I created the group “backup” and then edited the newly created group to include root as a member and the make install step completed with error.

After that the amadmin –version gave me my currrent build version.

As per your instruction install amanda 3.3.5 on my centos 6.5 but fail to install please see the below error.
chown root:backup /usr/local/sbin/amservice
chown: invalid group: `root:backup’
make[5]: *** [installperms-exec] Error 1
make[5]: Leaving directory `/etc/amanda-3.3.5/common-src’
make[4]: *** [install-exec-am] Error 2
make[4]: Leaving directory `/etc/amanda-3.3.5/common-src’
make[3]: *** [install-am] Error 2
make[3]: Leaving directory `/etc/amanda-3.3.5/common-src’
make[2]: *** [install] Error 2
make[2]: Leaving directory `/etc/amanda-3.3.5/common-src’
make[1]: *** [install-recursive] Error 1
make[1]: Leaving directory `/etc/amanda-3.3.5′
make: *** [install] Error 2
[root@NMS amanda-3.3.5]# amadmin –version
bash: amadmin: command not found
[root@NMS amanda-3.3.5]# amdump all
bash: amdump: command not found
[root@NMS amanda-3.3.5]# cd
[root@NMS ~]# amdump all
bash: amdump: command not found
[root@NMS ~]# amflush -f all
bash: amflush: command not found

Dear Rahul,
we are coming up with next article to cover all these soon.
Till then stay Tuned.

Welcome @ rediff