Data migration from postgres 8.4 to 9.4

Hello,
I need help in using postgresql 8.4 data in postgres 9.4 version. Do I
need to run any tool to achieve the same?

Steps i followed is ran postgresql 8.4 and 9.4, copied data from 8.4
instance to 9.4 and try to start postgresql 9.4 but no luck, getting below
error.

[root(at)ms-esmon esm-data]# su - postgres -c
"/opt/rh/rh-postgresql94/root/usr/bin/postgres -D
/var/ericsson/esm-data/postgresql-data/ 2>&1 &"
[root(at)ms-esmon esm-data]# LOG: skipping missing configuration file
"/var/ericsson/esm-data/postgresql-data/postgresql.auto.conf"
2018-04-16 06:52:01.546 GMT FATAL: database files are incompatible with
server
2018-04-16 06:52:01.546 GMT DETAIL: The data directory was initialized
by PostgreSQL version 8.4, which is not compatible with this version
9.4.9.

With Best Regards
Akshay
Ericsson OSS MON
Tata Consultancy Services
Mailto: akshay(dot)ballarpure(at)tcs(dot)com
Website: http://www.tcs.com
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