Hi ! I have Dell Poweredge 2650 server with RAID controller and Mikrotik said "no harddrive found" during installing process - I think Mikrotik don't support RAID controllers.
So, I have question: May I install CentOS on the server with XEN and then install Mikrotik on this system ? Is it possible ?

Yes it's possible, I have RouterOS running under Xen. However you can only use emulated NICs so performance suffers and this configuration is unsupported by MikroTik; they say it will probably never be supported due to how they do their licensing.

Problem is Hardware ID when copying disk image... its same.