Problem connect to external DB

[samguo]

I am trying to migrate OTRS server from Redhat 5 to 7 on redhat 5 it connected to external DB no problem, so I copied all entire OTRS folder to newserver redhat 7 then I run: /opt/otrs/bin/otrs.CheckDB.pl it have me following error

Can't load log backend module Kernel::System::Log::SysLog! Can't locate Sys/Syslog.pm in @INC (@INC contains: /opt/otrs/Custom /opt/otrs/Kernel/cpan-lib /opt/otrs /usr/local/lib64/perl5 /usr/local/share/perl5 /usr/lib64/perl5/vendor_perl /usr/share/perl5/vendor_perl /usr/lib64/perl5 /usr/share/perl5 .) at /opt/otrs/Kernel/System/Log/SysLog.pm line 17.
BEGIN failed--compilation aborted at /opt/otrs/Kernel/System/Log/SysLog.pm line 17.
Compilation failed in require at (eval 7) line 2.

Could anyone give me some advice on how to fix this please?

[jojo]

Read the manual (Installation chapter): http://doc.otrs.org and install the needed perl modules