Category: nfs-ganesha

Edit with systemctl edit to add restart on fail to a service – nfs-ganesha

A quick tip how to edit a service unit file under a c system like CentOS Stream 9 or Ubuntu. The best way is to edit it with the the tool “systemctl edit [service_name]”, which will trigger the default editor to open a temporary copy of the systemd unit file with the service name used with it. The default editor in the console is controlled by “EDITOR” variable and may be changed prior using the systemctl edit. After a successful manipulation of the system unit file the new one will be installed and a reload of the systemd unit files will be triggered with “systemctl daemon-reload” automatically. Indeed, it is just a text edit of a text file, which will do several actions when using “systemctl edit” command.

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systemctl cat service

systemd options ro restart a service on fail are:

[Service]
Restart=on-failure
RestartSec=5s

Here, the example is to add a restart-on-fail functionality to the nfs-ganesha service (NFS service). The systemctl edit may be used for many other changes to the systemd unit file under the console and it is the easiest and proper way.

SCREENSHOT 1) Use “systemctl edit” to edit a copy of the systemd override unit file.

do not insert anything at the end of the comments or below the second red line comments – “### Lines below this comment will be discarded”. This temporary override file includes a systemd unit file of the service, which is opened for editing. The result override.conf file will only include the added lines, no other comments shown below the second red line.

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systemctl edit opened

Keep on reading!

Migrate from NFS Kernel Server to NFS-Ganesha server under CentOS Stream 9

This article is to show how to migrate from the NFS kernel server to the NFS-Ganesha server under CentOS Stream 9. The most important thing for migrating from one program to another program is how much downtime will be and what is expected to be done by the clients. In this case, what the clients are needed to do when NFS-Ganesha is used for the server?

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install nfs ganesha

Here are the main points when migrating from NFS Kernel Server to the NFS-Ganesha:

  • The nfs-tuils and nfs-ganesha packages and in general, the two software, are perfectly fine installed on the same system. There are no conflicts when NFS Kernel Server and the NFS-Ganesha server are installed at the same time on the same system.
  • The clients, do not need to do anything, except remount the NFS mounts.
  • It should be installed a new community repository by installing the centos-release-nfs-ganesha5 package. The Special Interest Groups (SIG) maintains the repository and the group is within the CentOS community

For installation of NFS-Ganesha and a detailed information check out the older article on the subject – Simple export of a ext4 directory with NFS Ganesha 3.5 server in CentOS 8 with SELinux enforcing, Simple export of a ext4 directory with NFS Ganesha 3.5 server in CentOS 8 without SELinux and Create and export a GlusterFS volume with NFS-Ganesha in CentOS 8

Prerequisite – NFS Kernel Configuration

NFS Kernel Server is installed with nfs-utils packages (and its dependencies) and it has the following simple configuration:

[root@srv ~]# cat /etc/exports
/mnt/storage           192.168.0.0/24(rw,sync,no_root_squash,no_subtree_check)

And here are the NFS services on the system:

[root@srv ~]# systemctl |grep nfs
  proc-fs-nfsd.mount                                         loaded active mounted   NFSD configuration filesystem
  var-lib-nfs-rpc_pipefs.mount                               loaded active mounted   RPC Pipe File System
  nfs-idmapd.service                                         loaded active running   NFSv4 ID-name mapping service
  nfs-mountd.service                                         loaded active running   NFS Mount Daemon
  nfs-server.service                                         loaded active exited    NFS server and services
  nfsdcld.service                                            loaded active running   NFSv4 Client Tracking Daemon
  nfs-client.target                                          loaded active active    NFS client services

The server’s firewall has been tuned for the NFS kernel server, so no need to edit anything in the firewall for the NFS-Ganesha server.
Keep on reading!

Create and export a GlusterFS volume with NFS-Ganesha in CentOS 8

GlusterFS built-in NFS server supports only NFS version 3. GlusterFS offers NFS exports using NFS-Ganesha, which supports NFS version 3 and 4 protocols.
NFS-Ganesha server is a user-mode file sharing server, which offers a GlusterFS plugin to export GlusterFS volumes. In the following article, the NSF-Ganesha and GlusterFS are installed and a simple GlusterFS volume is created and then exported through NFS 3 and 4 version protocols.
The version of the software in this article:

  • CentOS Stream release 8 (25.04.2021)
  • GlusterFS 8.4
  • NFS-Ganesha 3.5

STEP 1) Install GlusterFS.

dnf install -y centos-release-gluster
dnf install -y glusterfs-server

The first line will installs a new repository under the SIG management – https://wiki.centos.org/SpecialInterestGroup/Storage. The second line installs the GlusterFS server.

STEP 2) Install NFS-Ganesha.

dnf install -y centos-release-nfs-ganesha30
dnf install -y nfs-ganesha nfs-ganesha-gluster

The first line again installs a new repository under the SIG management and the second line installs the NFS-Ganesha server with Gluster plugin.

STEP 3) Create GlusterFS volume

Start the GlusterFS server and create a simple 3 replicas volume with:
Start the GlusterFS on all the three nodes and enable the GlusterFS communication between the three nodes using firewall-cmd utility. So execute the following commands:

systemctl start glusterd
firewall-cmd --permanent --new-zone=glusternodes
firewall-cmd --permanent --zone=glusternodes --add-source=192.168.0.200
firewall-cmd --permanent --zone=glusternodes --add-source=192.168.0.201
firewall-cmd --permanent --zone=glusternodes --add-source=192.168.0.202
firewall-cmd --permanent --zone=glusternodes --add-service=glusterfs
firewall-cmd --reload

On the first node create the GlusterFS volume. First, add the glnode2 and glnode3 to the cluster.

gluster peer probe glnode2
gluster peer probe glnode3
gluster volume create VOL1 replica 3 transport tcp glnode1:/mnt/storage/gluster/brick glnode2:/mnt/storage/gluster/brick glnode3:/mnt/storage/gluster/brick
gluster volume start VOL1

Keep on reading!

Simple export of a ext4 directory with NFS Ganesha 3.5 server in CentOS 8 with SELinux enforcing

In fact, this article is a continuation of the previous NFS Ganesha article – Simple export of an ext4 directory with NFS Ganesha 3.5 server in CentOS 8 without SELinux because it has the same purpose to export a directory residing on an ext4 file system under CentOS 8 Stream, but this time the SELinux is enabled and it is in enforcing mode! There is a need for this additional article because the SELinux is not enabled in many user configurations (despite being wrong!) and the SELinux configuration may add complexity to the first article, which could lead to misleading thoughts. The previous article might be a little bit more detailed, so the reader could check it, too.
It’s worth mentioning the key points of NFS-Ganesha:

  • a user-mode file sharing server
  • supports NFS 3, 4.x and 9P
  • using plugins for different file systems
  • CentOS Storage Special Interest Group offers a file repository with NFS-Ganesha server
  • supports file systems like ext4, xfs, brtfs, zfs and more. There are sample configurations: https://github.com/phdeniel/nfs-ganesha/tree/master/src/config_samples
  • supports cluster and/or distributed file systems like GlusterFS, Ceph, GPFS, HPSS, Lustre
  • Current version 3.5 and it is included in the official SIG CentOS Storage Special Interest Group repository.

This article assumes the reader has a clean CentOS 8 Stream installation with SELinux in enforcing mode.

STEP 1) Install the repository and NFS-Ganesha software

NFS-Ganesha 3 packages are from the CentOS Storage SIG repository, which is a good repository and may be trusted.

dnf install -y centos-release-nfs-ganesha30
dnf install -y nfs-ganesha nfs-ganesha-vfs nfs-ganesha-selinux

STEP 2) Configuration for exporting a directory.

There are two files under /etc/ganesha/:

ganesha.conf
vfs.conf

ganesha.conf includes global configuration and NFS share configuration. Each export path begins with the keyword EXPORT followed by a block ebraced by brackets {}.
vfs.conf includes a simple example for the VFS plugin, but this configuration file is not used by the NFS Ganesha server. It is just a sample file.
Here is a simple configuration, which exports /mnt/storage with Read/Write permissions to a single IP. Just add at the end of the file /etc/ganesha/ganesha.conf contains:

 
EXPORT
{
        Export_Id = 2;
        Path = /mnt/storage1;
        Pseudo = /mnt/storage1;
        Protocols = 3,4;
        Access_Type = RW;
        Squash = None;
        FSAL
        {
                Name = VFS;
        }
        CLIENT
        {
                Clients = 192.168.0.12;
        }
}

STEP 3) Start the server and mount the exported directory. Configure the firewall.

Start the server, enable the service to start on boot and then configure the firewall to pass the NFS requests:

systemctl start nfs-ganesha
systemctl enable nfs-ganesha
firewall-cmd --permanent --zone=public --add-service=nfs
firewall-cmd --reload

Keep on reading!

Simple export of a ext4 directory with NFS Ganesha 3.5 server in CentOS 8 without SELinux

NFS Ganesha is a user-mode file sharing server, which supports NFS 3 and 4.x versions and 9P. NFS Ganesha has several interesting plugins that support exporting files from the cluster and distributed file systems like Ceph and Glusterfs Exporting a file system with NFS Ganesha is simple enough if you do not use SELinux or SELinux is in permissive mode!
This article is to show how to export a server’s directory using NFS protocol Just to note the NFS-Ganesha is tested and supports ext2/ext3/ext4, xfs, brtfs, zfs file systems as of version 3.5 (check the manual for xfs, brtfs and zfs exports – here are sample configurations for them https://github.com/phdeniel/nfs-ganesha/tree/master/src/config_samples). To be able to export a file directory the VFS Ganesha plugin is used. A clean install of minimal CentOS 8 Stream is used so the installation log may differ significantly from the user’s log but the user will see all the dependencies, which are required for this setup.

STEP 1) Install the repository and NFS-Ganesha software

NFS-Ganesha 3 packages are from the CentOS Storage SIG repository, which is a good repository and may be trusted.

dnf install -y centos-release-nfs-ganesha30
dnf install -y nfs-ganesha nfs-ganesha-vfs

STEP 2) Configuration for exporting a directory.

There are two files under /etc/ganesha/:

ganesha.conf
vfs.conf

ganesha.conf includes global configuration and NFS share configuration. Each export path begins with the keyword EXPORT followed by a block ebraced by brackets {}.
vfs.conf includes a simple example for the VFS plugin, but this configuration file is not used by the NFS Ganesha server. It is just a sample file.
Here is a simple configuration, which exports /mnt/storage with Read/Write permissions to a single IP. Just add at the end of the file /etc/ganesha/ganesha.conf contains:

 
EXPORT
{
        Export_Id = 2;
        Path = /mnt/storage1;
        Pseudo = /mnt/storage1;
        Protocols = 3,4;
        Access_Type = RW;
        Squash = None;
        FSAL
        {
                Name = VFS;
        }
        CLIENT
        {
                Clients = 192.168.0.12;
        }
}

STEP 3) Start the server and mount the exported directory. Configure the firewall.

Start the server, enable the service to start on boot and then configure the firewall to pass the NFS requests:

systemctl start nfs-ganesha
systemctl enable nfs-ganesha
firewall-cmd --permanent --zone=public --add-service=nfs
firewall-cmd --reload

Keep on reading!