ISR Computing -

RHCE NFS Configuration

Basic lab setup:

rhel5 - NFS Server (IP: 192.168.88.5)

rhel6 - NFS Client (IP: 192.168.88.6)

3 users: olivia, garry, paul

Check that NFS fileystem is supported by your system:

[root@rhel5 /]# cat /proc/filesystems | grep nfs
nodev   nfsd
[root@rhel5 /]# 

To list NFS shares:

[root@rhel5 ~]# showmount -e
Export list for rhel5:
/home 192.168.88.0/24
/inst 192.168.88.0/24
[root@rhel5 ~]# 

Mount NFS volume:

#mount -t nfs 192.168.88.5:/home /home

Unmount NFS volume

#umount -f 192.168.88.5:/home

Deciding How to Mount File Systems
Q: Remote file systems frequently, such as home directories?
A:

1. The /etc/vfstab file, which will automatically mount the file system when the system is booted in multi-user state.
2. AutoFS, which will automatically mount or unmount the file system when you change into (mount) or out of (unmount) the directory.

#service autofs status
#nano /etc/auto.master
/home   /etc/auto.home

If we want to mount users one by one:

[root@rhel6 /]# cat /etc/auto.home
*       -fstype=nfs,rw,intr,rsize=32768,wsize=32768,hard,bg,nosuid,noexec,tcp   192.168.88.5:/home/&
/OR
olivia  -fstype=nfs,rw,intr,rsize=32768,wsize=32768,hard,bg,nosuid,noexec,tcp   192.168.88.5:/home/olivia
garry   -fstype=nfs,rw,intr,rsize=32768,wsize=32768,hard,bg,nosuid,noexec,tcp   192.168.88.5:/home/garry
paul    -fstype=nfs,rw,intr,rsize=32768,wsize=32768,hard,bg,nosuid,noexec,tcp   192.168.88.5:/home/paul

Please note that automount will use an auto.master NIS map by default.
Thus, to force automounter to use local files, you must start is as follows:

  # automount -d -f /etc/auto.master &

The other option is to edit /etc/sysconfig/autofs and uncomment line below:

#MASTER_MAP_NAME="auto.master"

To enable logging, edit /etc/sysconfig/autofs and add line below:

LOGGING="debug"

When you will mount share, they will mount automatically, but it will take some time to mount.

Mount options:

-ro     Read only
-rw     Mount the filesystem read and write, but can be restricted by the server, and a warning is flagged
-soft   if the server fails to respond, return an error after the timeout period ( -timeo=value ) expires and don't bother to try again
-hard   if the server fails to respond, retry until it does respond
-bg     do the retrys in background mode
-nosuid Do not allow executables on the mounted filesystem to run as setuid.
-fstype file system type of the remote partition to mount
                ext2    linux native
                nfs     NFS type
                iso9660 CDROM
-user   Allow users to mount the filesystem
-noexec Don't allow execution of files from this filesystem
-nosuid Don't allow programs in this filesystem to run as setuid or setgid

1) How to add iptables rules to allow NFS communication
This is a more complex but right solution to the given problem.
First we need to set static port for nfs services such as rquotad, mountd, statd, and lockd by editing /etc/sysconfig/nfs file.
Add/uncomment following lines in your /etc/sysconfig/nfs file:

MOUNTD_NFS_V2=no
MOUNTD_NFS_V3=no
MOUNTD_NFS_V4=yes
LOCKD_TCPPORT=32803
LOCKD_UDPPORT=32769
MOUNTD_PORT=892
STATD_PORT=662

To configure a firewall to allow NFS:

1. Allow TCP and UDP port 2049 for NFS.
2. Allow TCP and UDP port 111 (portmap/sunrpc).
3. Allow the TCP and UDP port specified with MOUNTD_PORT="892"
4. Allow the TCP and UDP port specified with STATD_PORT="662"
5. Allow the TCP port specified with LOCKD_TCPPORT="32803"
6. Allow the UDP port specified with LOCKD_UDPPORT="32769"

[root@rhel5 sysconfig]# cat /etc/services
nfs             2049/tcp        nfsd
nfs             2049/udp        nfsd
sunrpc          111/tcp         portmapper      # RPC 4.0 portmapper TCP
sunrpc          111/udp         portmapper      # RPC 4.0 portmapper UDP

2) How to restart NFSD daemon

# /etc/init.d/nfs restart
# /etc/init.d/nfslock restart

service nfs restart
service nfslock restart

On Server, check portmap
# rpcinfo -p

[root@rhel5 sysconfig]# rpcinfo -p
   program vers proto   port
    100000    2   tcp    111  portmapper
    100000    2   udp    111  portmapper
    100011    1   udp    679  rquotad
    100011    2   udp    679  rquotad
    100011    1   tcp    682  rquotad
    100011    2   tcp    682  rquotad
    100003    2   udp   2049  nfs
    100003    3   udp   2049  nfs
    100003    4   udp   2049  nfs
    100003    2   tcp   2049  nfs
    100003    3   tcp   2049  nfs
    100003    4   tcp   2049  nfs
    100021    1   udp  32769  nlockmgr
    100021    3   udp  32769  nlockmgr
    100021    4   udp  32769  nlockmgr
    100021    1   tcp  32803  nlockmgr
    100021    3   tcp  32803  nlockmgr
    100021    4   tcp  32803  nlockmgr
    100005    1   udp    892  mountd
    100005    1   tcp    892  mountd
    100024    1   udp    662  status
    100024    1   tcp    662  status
[root@rhel5 sysconfig]#