在搭建nfs的時候，showmount報錯如下
[root@yzlc1 ~]# showmount -e 192.xx.xx.151
mount clntudp_create: RPC: Port mapper failure - RPC: Unable to receive
源端查看nfs是否打開
[root@LZL ~]# exportfs -rv
exporting *:/backup
源端/backup目錄已經在exporting狀態了
檢查發現本地防火牆，selinux都已經關閉，源端selinux關閉，但是防火牆沒有關
報錯是因爲沒有關閉防火牆
[root@LZL ~]# systemctl status firewalld
● firewalld.service - firewalld - dynamic firewall daemon
Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled; vendor preset: enabled)
Active: active (running) since Wed 2020-05-27 19:07:44 CST; 16h ago
Docs: man:firewalld(1)
Main PID: 10612 (firewalld)
CGroup: /system.slice/firewalld.service
└─10612 /usr/bin/python -Es /usr/sbin/firewalld --nofork --nopid
May 27 19:07:44 CISServer systemd[1]: Starting firewalld - dynamic firewall daemon...
May 27 19:07:44 CISServer systemd[1]: Started firewalld - dynamic firewall daemon.
防火牆狀態爲打開，關閉防火牆
[root@CISServer ~]# systemctl stop firewalld
[root@CISServer ~]#
[root@yzlc1 ~]# showmount -e 192.xx.xx.151
Export list for 192.xx.xx.151:
/backup *
這個時候就可以直接mount
mount 192.xx.xx.151:/backup /backup
如果需要rman備份到nfs上，需要在mount時增加參數，不然會備份報錯
mount -t nfs -o rw,bg,noac,hard,nointr,rsize=32768,wsize=32768,nolock,proto=tcp,actimeo=0,vers=3,timeo=600 192.xx.xx.151:/backup /backup