vfs.dev.read not supported on centos5 machine

[just2blue4u]

[root@server ~]# zabbix_agentd -t agent.version
agent.version                                 [s|1.4.5]
[root@server ~]# zabbix_agentd -t vfs.dev.read
vfs.dev.read[]                                [m|ZBX_NOTSUPPORTED]
[root@server ~]# zabbix_agentd -t vfs.dev.read[,operations]
vfs.dev.read[,operations]                     [m|ZBX_NOTSUPPORTED]
[root@server ~]# zabbix_agentd -t vfs.dev.read[all,sectors]
vfs.dev.read[all,sectors]                     [m|ZBX_NOTSUPPORTED]
[root@server ~]#

this is on all my servers. Any clues why it could be?

Zabbix logs don't show anything

[tekknokrat]

nothing else with 1.6 version although its documented item in handbook