NAS

NAS support is only available in the VMmanager Infrastructure version.

NAS (Network Attached Storage) is a network storage that provides file-level access to data. NAS can be used to store VM images and linked clones.

NAS restrictions

Migration of VMs with disks in a NAS is only available to another NAS or file storage.

GlusterFS

Using VMmanager cluster nodes as GlusterFS nodes is not supported. This can cause:

VM and storage performance degradation due to resource access conflicts;
risk of data loss and reduced storage availability due to high server load.

How NAS works

To connect a NAS to a cluster node, a cluster file system or NFS must be configured on the NAS device. A cluster file system is a system that can be used simultaneously by multiple servers. Such systems include OCFS2, GlusterFS, CephFS, GFS2, and others.

VMmanager cluster nodes access the NAS through a mounted directory that is specified when the storage is connected.

Configuring the file system

The configuration of NFS on servers with AlmaLinux OS is considered as an example. You can also use a file system based on OCFS2, GlusterFS, CephFS, or GFS2.

On the storage server:
1. Create a directory for mounting. For example, /mnt/nfsshare/:
```
mkdir -p /mnt/nfsshare
```
2. Grant permissions to access the directory:
```
chown nobody:nobody /mnt/nfsshare
```
```
chmod 777 /mnt/nfsshare
```
3. Install the NFS server software:
```
dnf update -y
```
```
dnf -y install nfs-utils
```
4. Run the service and add it to the autostart:
```
systemctl start nfs-server.service
```
```
systemctl enable nfs-server.service
```
5. Add the IP addresses of the cluster nodes to the /etc/exports configuration file. To do this, run the command for each cluster node:
```
echo '/mnt/nfsshare <NODE_IP>(rw,sync,no_subtree_check,no_root_squash)' >> /etc/exports && exportfs -vra
```
  Comments to the command
  <NODE_IP> — IP address of the cluster node
6. Allow connections to NFS in the firewall settings:
```
firewall-cmd --permanent --add-port=2049/tcp
```
```
firewall-cmd --reload
```
On the cluster nodes:
1. Install the NFS client software:
```
dnf -y install nfs-utils nfs4-acl-tools
```
2. Run the service and add it to the autostart:
```
systemctl start nfs-client.target
```
```
systemctl enable nfs-client.target
```
3. Create a directory to which the storage will be mounted. For example, /mnt/nas/:
```
mkdir -p /mnt/nas
```
4. Mount the storage:
  If high availability is disabled in the cluster
```
mount.nfs4 <NAS_IP>:/mnt/nfsshare /mnt/nas
```
  If high availability is enabled in the cluster
```
mount.nfs4 -o user,soft,timeo=5,retry=1 <NAS_IP>:/mnt/nfsshare /mnt/nas && chmod -R 777 /mnt/nas
```
  Comments to the commands
  <NAS_IP> — IP address of the storage
5. Add the mounted partition to the autostart. To do this, add a line to the /etc/fstab file:
```
<NAS_IP>:/mnt/nfsshare        /mnt/nas       nfs rw,suid,dev,auto,nouser,sync    0 0
```
  Comments
  <NAS_IP> — IP address of the storage

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