Note: This is an RHCSA 7 exam objective.

NFS network file system

To mount and unmount NFS network file systems, you need to set up a NFS server.

Install the NFS client package:

# yum install -y nfs-utils

Let’s assume that the /home/tools directory is exported by the nfsserver server. If no working DNS, add an entry in the /etc/hosts file with the nfsserver name and its IP address.

Activate at boot and start the nfs-idmap service (RHEL 7.0 only):

# systemctl enable nfs-idmap && systemctl start nfs-idmap

Note: The nfs-idmap service is only required by NFSv4 when setting ACL by names or to display user/group names. It doesn’t allow you any UID/GID mismatches between clients and server. All permission checks are still done with the UID/GID used by the server.

Activate at boot and start the nfs-client target (RHEL 7.1 and after):

# systemctl enable nfs-client.target && systemctl start nfs-client.target

Edit the /etc/fstab file and add the following line:

nfsserver:/home/tools /mnt nfs4 defaults 0 0

Execute the /etc/fstab file configuration:

# mount -a

To check the current configuration, type:

# mount | grep nfsserver
nfsserver:/home/tools on /mnt type nfs4 (rw,relatime,vers=4.0,rsize=131072,wsize=131072,namlen=255,hard,proto=tcp,port=0,timeo=600,retrans=2,sec=sys,clientaddr=192.168.1.42,local_lock=none,addr=192.168.1.49)

To unmount the NFS mounted directory, remove the previous line from the /etc/fstab file and type:

# umount /mnt

Note: if you get a message like “/mnt: device is busy”, to check that you are not in the mounted directory and no process is using it, type:

# fuser /mnt

CIFS network file system

To mount and unmount CIFS network file systems, you need to set up a CIFS file server.

Install the Samba client packages:

# yum install -y cifs-utils
# yum install -y samba-client

Let’s assume that the /shared directory is exported by the smbserver server. If no working DNS, add an entry in the /etc/hosts file with the smbserver name and its IP address.

Edit the /etc/fstab file and add the following line:

//smbserver/shared /mnt cifs rw,username=user01,password=pass 0 0

Execute the /etc/fstab file configuration:

# mount -a

To check the current configuration, type:

# mount | grep smbserver
//smbserver/shared on /mnt type cifs (rw,relatime,vers=1.0,cache=strict,username=user01,domain=MYSERVER,uid=0,noforceuid,gid=0,noforcegid,addr=192.168.1.48,unix,posixpaths,serverino,acl,rsize=1048576,wsize=65536,actimeo=1)

To unmount the CIFS mounted directory, remove the previous line from the /etc/fstab file and type:

# umount /mnt

To learn more about the Automounter, go to the LDAP client configuration tutorial.