Mounting File Storage for Classic on Red Hat Linux

Use these instructions to connect a Red Hat Enterprise Linux®-based IBM Cloud® Compute instance to a Network File System (NFS) share. For more information about how to order IBM Cloud® File Storage for Classic, see the Getting started tutorial.

Before you begin, make sure that the host that is to access the File Storage for Classic volume is authorized. For more information, see Authorizing the host in the console Authorizing the host from the CLI Authorizing the host with Terraform.

Mounting the File Storage for Classic share

Install the required tools.
```
# dnf install nfs-utils
```
Create a directory in your instance.
```
mkdir /mnt/test
```
Obtain the mount point information from the File Storage for Classic Details page in the console, with an API call (SoftLayer_Network_Storage::getNetworkMountAddress()), or by looking at the ibm_storage_file resource in Terraform.
Mount the remote share.
```
# mount -t nfs -o <options> <host:mount_point> /mnt
```
Example for storage_as_a_service volumes.
```
#mount -t nfs -o nfsvers=3 fsf-wdc0403a-fz.service.softlayer.com:/IBM02SEV1414935_66/data01 /mnt
```
Example for enterprise volumes.
```
# mount -t nfs -o nfsvers=3 nfshou0201d-fz.service.softlayer.com:/IBM01SEV1414935_2 /mnt
```
If you're using NFS 4.1, add sec=sys to the mount command to prevent file ownership issues. If you're using NFSv3 or NFS 4.1, add _netdev to wait for the storage to be mounted after all network components are started. For more information about the mount command and its options, see the mount(8) manual page.

Verify that the mount was successful by using the disk file system command.

# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/xvda2  25G  1.4G  22G    6%   /
/tmpfs     1.9G     0 1.9G    0%   /dev/shm
/dev/xvda1 97M    51M  42M   55%

Go to the mount point, and read/write files.
```
# touch /mnt/test
# ls -la /mnt
total 12
drwxr-xr-x   2 nobody nobody 4096 Sep 8 15:52 .
dr-xr-xr-x. 22 root   root   4096 Sep 8 14:30 ..
-rw-r--r--   1 nobody nobody    0 Sep 8 15:52 test
```
The files that are created by root have ownership of nobody:nobody. To display ownership correctly, the idmapd.conf needs to be updated with the correct domain settings. For more information, see the Implementing no_root_squash for NFS (optional) section.

Mount the remote share on start. To complete the setup, edit the file systems table (/etc/fstab) to add the remote share to the list of entries that are automatically mounted on startup:

(hostname):/(username) /mnt nfs_version options 0 0

See the following examples.

fsf-wdc0403a-fz.service.softlayer.com:/IBM02SEV1414935_66/data01 /mnt nfs nfsvers=3 0 0
fsf-wdc0403a-fz.service.softlayer.com:/IBM02SEV1414935_66/data01 /mnt nfs options 0 0
fsf-wdc0403a-fz.service.softlayer.com:/IBM02SEV1414935_66/data01 /mnt nfs4 options 0 0
fsf-wdc0403a-fz.service.softlayer.com:/IBM02SEV1414935_66/data01 /mnt nfs _netdev,nfsvers=3 0 0

For more information, see An introduction to the Linux /etc/fstab file.

Verify that the configuration file has no errors.
```
# mount -fav
```
If the command completes with no errors, your setup is complete.

Managing user permissions to the content of the mounted file share

As a system administrator, you can manage the access to data on the mounted file storage volume. After the file share is mounted, you can refine access control by using the chown and chmod commands to assign read, write, and execute permissions to individual users and groups. For more information, see Red Hat's tutorial: How to manage Linux permissions for users, groups, and others.

Implementing `no_root_squash` for NFS (optional)

By default, NFS downgrades any files that were created with the root permissions to the nobody user. This security feature prevents privileges from being shared unless they are requested.

Configuring no_root_squash allows root clients to retain root permissions on the remote NFS share.

For NFSv3, clients don't need to do anything; the no_root_squash simply works.
For NFSv4.1, you need to set the nfsv4 domain to: slnfsv4.com and start rpcidmapd, or a similar service that is used by your OS.

Example

From the host, set the domain setting in /etc/idmapd.conf.

#vi /etc/idmapd.conf
[General]
#Verbosity = 0
#The domain value should be set to the local NFSv4 domain name
#The default is the host's DNS domain name.
Domain = slnfsv4.com
[Mapping]
Nobody-User = nobody
Nobody-Group = nobody

Run nfsidmap -c.

Start rpcidmapd.

systemctl start rpcidmapd
systemctl enable rpcidmapd

Unmounting the file system

To unmount any currently mounted file system on your host, run the umount command with disk name or mount point name.

umount /dev/sdb

umount /mnt