NFS-phobic in Malaysia

I taught the EMC Cloud Infrastructure and Services (CIS) class last week and naturally, a few students came from the VMware space. I asked how they were implementing their storage and everyone said Fibre Channel.

I have spoken to a lot of people about this as well in the past, whether they are using SAN or NAS storage for VMware environments. And almost 99% would say SAN, either FC-SAN or iSCSI-based SAN. Why???

When I ask these people about deploying NFS, the usual reply would be related to performance.

NFS version 3 won the file sharing protocol race during its early days where Unix variants were prevalent, but no thanks to the Balkanization of Unices in the 90s. Furthermore, NFS lost quite a bit of ground between NFSv3 in 1995 and the coming out party of NFSv4.1 just 2 years ago. The in-between years were barren and NFS become quite a bit of a joke with “Need For Speed” or “No F*king Security“. That also could be a contributing factor to the NFS-phobia we see here in Malaysia.

I have experiences with both SAN and NAS and understood the respective protocols of Fibre Channel, iSCSI, NFS and CIFS, and I felt that NFS has been given unfair treatment by people in this country. For the uninformed, NFS is the only NAS protocol supported by VMware. CIFS, the Windows file sharing protocol, is not supported, probably for performance and latency reasons. However, if you catch up with high performance computing (HPC), clustering, or MPP (Massively Parallel Processing) resources, almost always you will read about NFS being involved in delivering very high performance I/O. So, why isn’t NFS proposed with confidence in VMware environments?

I have blogged about this before. And I want to use my blog today to reassert what I believe in and hope that more consideration can be given to NFS when it comes to performance, even for virtualized environments.

NFS performance is competitive when compared to Fibre Channel and in a lot of cases, better than iSCSI. It is just that the perception of poor performance in NFS is stuck in people’s mind and it is hard to change that. However, there are multiple credible sources that stated that NFS is comparable to Fibre Channel. Let me share with you one of the source that compared NFS with other transport protocols:

From the 2 graphs of IOPS and Latency, NFS fares well against other more popular transport protocols in VMware environments. Those NFS performance numbers, are probably not RDMA driven as well. Otherwise RDMA could very well boost the NFS numbers into even higher ground.

What is this RDMA (Remote Direct Memory Access)? RDMA is already making its presence felt quietly, and being used with transports like Infiniband and 10 Gigabit Ethernet. In fact, Oracle Solaris version 11 will use RDMA as the default transmission protocol whenever there is a presence of RDMA-enable NICs in the system. The diagram below shows where RDMA fits in in the network stack.

RDMA eliminates the need for the OS to participate in the delivery of data, and directly depositing the data from the initiator’s memory to the target’s memory. This eliminates traditional networking overheads such as buffers copying and setting up network data structures for the delivery. A little comparison of RDMA with traditional networking is shown below:

I was trying to find out how prevalent NFS was in supporting the fastest supercomputers in the world from the Top500 Supercomputing sites. I did not find details of NFS being used, but what I found was the Top500 supercomputers do not employ Fibre Channel SAN at all!  Most have either proprietary interconnects with some on Infiniband and 10 Gigabit Ethernet. I would presume that NFS would figure in most of them, and I am confident that NFS can be a protocol of choice for high performance environments, and even VMware environments.

The future looks bright for NFSv4. We are beginning to see the word of “parallel NFS (pNFS)” being thrown into conversations around here, and the awareness is there. NFS version 4.2 is just around the corner as well, promising greater enhancement to the protocol.


RedHat to acquire Gluster

This is breaking news. RedHat is to acquire Gluster!

What is Gluster? Gluster is a clustering Linux distribution started by Z Research under the direction of Anand Babu (who is currently Gluster’s CEO) aiming to commoditize supercomputing and supercomputing clustered storage. Gluster is open source but there is a commercial version as well. It runs on commodity 64-bit x86 hardware. The Gluster File System (GlusterFS) aggregates disks and memory resources into a pool of storage thru a single global namespace and accessed through multiple file-level protocols. The scale-out architecture is where storage resources can be added as a storage node in a building block fashion to meet performance and capacity demands, rather like what HP P4000 is doing to the block-level environment for SAN.

Gluster can integrated with most 64-bit Linux distros. This is done at the Linux user space but it can also be crafted at the Linux kernel space, where it is a software appliance, easily integrated into off-the-shelf 64-bit x86-64 platforms. This means that you can build a scale-out NAS pretty easily using your own hardware.

From an architecture standpoint, GlusterFS and its integration to a storage appliance looks like this:


Because it works in a modular add-on fashion, this architecture is distribution and extended by replicating the same architecture across additional x86-64 platforms (which is a storage node) as shown below.


It’s really easy to install Gluster and build the Scale Out NAS. I have been saving a couple videos about how Gluster is installed and I must say that it’s pretty easy. In less than 30 minutes, you can install your first Gluster storage node and then add additional nodes on the fly.

Enjoy the videos.

Video #1 (Gluster Installation)

(I have difficulty uploading the videos because WordPress requires me to purchase one of their solutions)

Video #2 (Creating and adding Storage Node in Gluster)

(I have difficulty uploading the videos because WordPress requires me to purchase one of their solutions)

Note: If you are interested to see the videos, please email to me at

This news gets me very excited because this is the perfect endorsement of what I have been saying all along. Storage networking and data management are the foundations of CLOUD and VIRTUALIZATION. Without data being stored and managed well, everything falls apart. And as I have mentioned many times before, this is a fantastic time to become an extra-ordinary storage engineer/consultant/architect/sales (maybe not!)