VMFS (Virtual Machine File System) vs NFS (Network File System)
VMFS is a block-based file system used to store virtual machines and snapshots. As a powerful clustered file system for virtualization, it can be shared between multiple ESXi hosts and virtual machines.
The Virtual Machine File System can be created on SCSI-based disks and on block storage accessed via Fibre Channel (FC), iSCSI and Fibre Channel over Ethernet (FCoE). It offers many virtalizatoin-based features such as simultaneous access to shared storage. When combined with shared storage, advanced vSphere features such as vMotion, DRS, HA, and FT are supported. Meanwhile, it can simultaneously write and read data to and from a single storage location.
NFS is short for Network File System. It is a network protocol which allows you to share files stored on a disk or disk array of server with other computers in the network. It is first produced in 1984 and developed by SUN Microsystems.
The NFS client is embedded in an ESXi host over TCP/IP to access a designed NFS volume that is located on a NAS server. The ESXi host mounts the volume as an NFS datastore, and uses it for storage needs. ESXi 6.0 or later version can support versions 3 and 4.1 of the NFS protocol.
Version of VMFS and NFS
Here are the main changes of VMFS and NFS version. With continuous upgrades and improvements, there are more and more features.
VMFS 1: It is used for ESX Server 1.x, and it doesn’t support cluster. VMware VMFS does not support concurrent access to multiple servers. Clustering is not available and can only be used on one server at a time.
VMFS 2: It is used for ESX Server 2.x or 3.x and doesn’t support the structure of directory.
VMFS 3: It is for vSphere 3.x or 4.x, and it supports the structure of directory. 50TB is the maximum size. In addition, VMFS 3 is not suitable for ESXi 7.0.
VMFS 5: It is used in vSphere 5.x and 6.x. The maximum single extent size is increased to 64 TB, and the maximum VMDK file size is increased to 62 for VMFS5.
VMFS 6: It is released in vSphere 6.5 and vSphere 6.7 is available to use it. It supports 4Kn and 512n storage devices and local devices.
1. TCP over IPv4 is now used as a standard
2. Was ratified as an Internet standard, described in RFC -3530
3. Client/server interactions are done using the GSS-API framework. Adding three security mechanisms to NFSv4: Kerberos, LIPKEY, and SPKM-3
4. Exported pseudo-file system on the server is mountable as a single common root on the client.
1. One of the most significant changes in v4.1 was adding multipath, by introducing better performance and availability through load balancing and multipathing
2. Kerberos and thus non-root user authentication are now supported.
3. Parallel NFS (pNFS) support
4. Directory Delegation and other file types
5. Improved compatibility with Microsoft Windows for Access Control Lists (ACLs)
6. LIPKEY and SPKM-3 are no longer required security mechanisms
7. Firewall-friendly single port operations
8. Replication and migration facilities
9. Support for parallelism and data striping
Tips: However, NFS 4.1 doesn’t support Storage I/O control, Site Recovery Manager and Storage DRS.
How to choose between VMFS and NFS
VMFS and NFS differ in the level of utilization. For the difference between VMFS and NFS, VMFS is a block level file system and NFS is based on file level. Besides, VMFS is created by vSphere, however, NFS datastore is created on the storage side and mounted with the shared folder on vSphere. Both VMFS and NFS have their own differences and advantages.
PROs of VMFS:
•Optimize virtual machine access and storage utilization,
• Enable automate CFS capability and perform high availability with lower management overhead
•Simplify disaster recovery and provisioning and administration of virtual machines
• Provide distributed infrastructure services for multiple vSphere hosts and intelligent cluster volume management.
PROs of NFS:
• VMDK Thin Provisioning by default
• De-duplication (file, block, variable-block, and application-aware)
• Backup and Restore Granularity
• Virtual Machines stored and manage in groups
• Use of ILM and HSM, or QoS (can also be used with VMFS)
• Maximum Volume Size (depending on Storage Array vendor)
Is it still necessary to use backup for datastore protection
VMFS and NFS are both reliable and mature to be used in VMware environment. However, if hardware failure and power-outage happen, it cannot avoid data loss in datastore. With the built-in features, you can backup VM in datastore such as download VM files, copy VM or migrate VM to another datastore manually. To provide automatic and more secure backups for multiple virtual machines, a professional software is important for you. In this part, I will introduce how to protect your VM comprehensively in the event of disaster using AOMEI Cyber Backup that is a professional backup software that automates backup tasks with a reliable backup strategy and always secure your VMware environment.
Always protect VM: automate reliable backups for long-term data protection, and perform hot backup anytime.
Flexible Backup Strategies: set up full backup for entire VM, or incremental/differential backup for only changed data, and configure retention policy.
Instant disaster recovery: restore the VM backup to normal state in a flash or migrate the VM to antoher host quicly which reduces the financial losses and business-critical downtime.
How to safeguard VM efficiently with backup software
1. Access to AOMEI Cyber Backup, and add devices.
2. Click Backup Task >> Create New Task.
3. In the open window, name the backup task and choose VMware ESXi and select the virtual machines with important workloads for backup.
4. Target: Specify a destination to store VM files such as local or network.
5. Schedule: Select backup strategies as full / incremental / differential backup and time to run the task.
6. Backup Cleanup: Specify the backup retention policies for each backup to delete unwanted backups automatically which saves storage and additional costs on hardware.
Then go to Start backup now or later. With a professional software, it makes data protection easier and safer. Try AOMEI Cyber Backup to offer continuous protection for your VM data.
Additional information about types of datastore
In addition to VMFS and NFS, there are still 2 types used for storage in VMware environment such as vSAN and vVol.
vSAN: It aggregates all local capacity devices available on the hosts into a single datastore shared by all hosts in the vSAN cluster. See the Administering VMware vSAN documentation.
vVol: Virtual Volumes datastore represents a storage container in vCenter Server and vSphere Client.
Did you know the difference between VMFS and NFS after reading this article? VMFS and NFS are efficient to be used in VMware environment. You can choose the suitable one according to your requirements of storage.
If you pursue comprehensive and secure virtual machine backup solutions, don't forget to use backup.