Changing hostname of NS-120 & VNX-5300

Hello All

Could someone help me in changing the hostname for my NS-120 and VNX-5300?

Currently, hostname is emcnas_i0

[root@emcnas_i0 ~]#

Existing /etc/hosts has

192.168.47.251  emcnas_i0   emcnas_i0

Tried adding 2 different combinations and rebooted. No affect.

192.168.47.251  test    emcnas_i0

192.168.47.251  test    test

BR//

RG