iSCSI vs NFS

Difference Between iSCSI and NFS

iSCSI or Internet Small Computer System Interface is a block transport layer protocol that works mainly on a block-level protocol interface. Block protocol can also directly access the storage and control the data flow inwards or outwards through a protocol SCSI. The Source and Target data are kerborized as they are highly encrypted at the iSCSI Initiator (source) level and decrypted upon its arrival at the iSCSI Target (destination) level. The parallel accessing of data is not possible in the iSCSI interface as it allows the data to share between the two hops. iSCSI can be considered only when there is data transfer between LAN (Local Area Network) or WAN (Wide Area Network) as the data accessing is very fast.

Advantages of iSCSI

• It aims to use a session between the client and the server to communicate the stream between the two (client and server).
• It supports multiple connections into a session.
• It supports an advanced method of error recovery using connection allegiance switching between the servers.

NFS or Network File System was designed in the year 1984 by Sun Microsystems. NFS is a distributed file system protocol that allows the data to be shared among different machines connected to the same network. It is very similar to accessing the remote machine’s data to access the local storage data. The parallel accessing among multiple clients is handled by NFS Service, which is based on the locking of resources. NFS also allows the admin to plug into a portion of the file system on the server that other users or clients can then use in the network-based interface on the user’s respective privileges.

NFS Versions

Following are the different versions of NFS:

1. NFSv3: With the increase in the versions, the versions are improvised with enhancements. NFSv3 includes:

• Support of 64-bit file size to handle data or files that are larger than 2GB.
• Supports multiple writes on the server, and thus write performance is increased.
• High-level authentication is supported.

2. NFSv4: version 4 includes high-performance enhancements, high-level security to the files. It also provides protocol support for cluster deployments to access the files among different servers parallelly. Some of the key features of NFSv4 are:

• It integrates the number of protocols like NFS, NLM, NSM together into a single protocol to access files across the firewalls.
• High-level authentication is supported using the GSS API.

Head to Head Comparison Between iSCSI and NFS (Infographics)

Below are the top 7 differences between ISCSI vs NFS:

Key Difference Between iSCSI vs NFS

NFS and iSCSI are pretty much different from each other. Let us look at the key differences:

• Definition: NFS is used to share data among multiple machines within the server. It is a file-sharing protocol. ISCSI is considered to share the data between the client and the server. It is basically a single channel architecture to share the files.
• Operating System: NFS works on Linux and Windows OS, whereas ISCSI works on Windows OS.
• Protocols: NFS is mainly a file-sharing protocol, while ISCSI is a block-level based protocol.
• File System: At the server level, the file system is handled in NFS. Guest OS takes care of the file system.
• File Read Option: As the data is NFS is placed at the server level, the client will not have access to read the data and metadata. This option of reading the data and metadata is handled in ISCSI as the data is placed at the client level.
• Efficiency: NFS is more efficient as it is a shared protocol and thus can be easily implemented by the users. ISCSI is a little difficult to handle as we need to configure host parameters and all to implement it.

Comparison Table of iSCSI vs NFS

Let’s discuss the topmost comparison between iSCSI vs NFS:

iSCSI	NFS
iSCSI should be considered for sharing the data between single-channel architecture(client-server).	NFS is used to share data among multiple client machines concurrently.
iSCSI is for Windows OS.	NFS for Linux or Windows operating systems.
Block level-based sharing.	File-Based sharing.
Guest OS takes care of File System.	NFS server takes care of File System.
iSCSI enables a single client for each volume on the block level.	NFS enables files to be shared among multiple servers.
In iSCSI, the File system is placed at the client level, so both data and metadata can be read.	In NFS, the File system is placed at the server level.
iSCSI is a little difficult to handle and implement because we need to configure hosts, storage options, VLANS, etc., just to configure ISCSI in our system.	NFS is a protocol that is more efficient and streamlined. As it is a shared protocol, it makes the client or user to implement it easily.

Features of iSCSI vs NFS

Given below are the features of ISCSI vs NFS:

Features of iSCSI

• IP Routing: One of the important advantages of ISCSI is that it uses TCP/IP Protocol. TCP/IP allows long-distance IP routing without the need for external gateway hardware. It also provides high flexibility and a huge storage network environment.
• Security: Internet Security Protocol is used for securing IP traffic in the network by authenticating and encrypting each data packets received in the network.
• Storage Array: iSCSI targets in a large storage array. The arrays can be free software-based or commercial products. It usually provides unique iSCSI targets for several clients or users.
• Standard Ethernet: iSCSI uses Standard Ethernet, and because of this, it does not require expensive components to be built for this protocol.

Features of NFS

• Remote Procedural Call (RPC): RPC is available for both the servers – NFS and Client for NFS. This service replaces the Transport Device Interface for better support and best scalability.
• Kerberization Options: NFS is a kerborized file system interface. We also get additional Kerberos privacy like Krb5p to support the existing Kerberos options like krb5 and krb5i.
• Mount Volume Point: This lets you access large volumes mounted under NFS4.1 V.
• Multiple Port Extensions: This feature supports RPC ports that are firewall-friendly and easy usage by the clients.
• Firewall Friendly: The advantage of NFSv4 is that it uses only one TCP Port -2049 to run the services, which simplify the usage of protocols across the firewalls.

Which one to use – NFS or iSCSI?

From the above analysis, it is clearly concluded that NFS Protocol is much better than iSCSI. Whether you use small or large, or medium files, NFS works very seamlessly and in an effective way compared to iSCSI. From the storage point of view, NFS will be the first choice, and then iSCSI will be coming next to NFS.

Except for the situation where we need to boot from SAN or run any Hyper-V, NFS is always a better choice from the developer’s point of view.

• NFS Security Level: NFS service supports Kerberos v5 client-server interface. For Kerberos V5 authentication, the mount and share commands have been altered in NFS Version 3. The Solaris 2.6 version release has been improvised to make the file system accessible through the server’s firewalls. NFS Version 4 is fully integrated with all the security that was added to mount the protocol.
• iSCSI Security Level: The main security risk in iSCSI SANs is that the hackers can transmit the storage data over the system or the server. With ACLs (Access Control Lists), storage admins can take precautions to lock the user privileges information.

Conclusion

With the above discussions, it is clear that the usage of NFS is much better than iSCSI. Unless we need to boot from SAN or run any Hyper-V files, we are always free to use NFS. Finally, it is based on your requirements; you can either use iSCSI or NFS. Both the File Systems are compared with all their pros and cons.

This has been a guide to iSCSI vs NFS. Here we discuss the key differences, features with infographics and comparison table, respectively. You may also have a look at the following articles to learn more –

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3. C vs C++
4. CIFS vs NFS