Monthly Archives: August 2013

The Evolving Role of IT Professionals

I started my career in software development.  I wrote codes, performed system analysis, and software quality assurance.   Then I switched to system and network administration, and infrastructure architecture.   While the roles of software developers may not change that much (software programs need to be created), the roles of IT administrators, architects, analysts, and IT departments in general are changing.  This is due to cheap hardware, smarter software and appliances, and the availability of the cloud.

I still remember some time ago when I would spend a lot of time troubleshooting a system.  Today, due to redundant systems, off the shelves and online applications, and the use of appliances, troubleshooting times have been reduced to a minimum.  When a component breaks, it’s easy to replace it.

IT companies are now selling converged network, server, and storage in a box which eliminated the need for elaborate architecture and implementation and has simplified IT operations.

With virtualization and the “cloud”, more and more applications and IT services (infrastructure as a service, software as a service, etc.) are being available online.

When it comes to IT, companies now have various choices – host their IT services externally via public cloud, build IT systems in house, or use the combination of the two.

Thus, the future role of IT professionals will be like brokers.  When the business comes to them for a need, they should be able to deliver quickly and provide the best IT solution.  They should be able to determine when to use the public cloud and when to use internal IT systems.  The key is to understand the business. For instance, it may not make sense to put data in the cloud if you are concerned about security or if your company is regulated by the government.  If your company is small, it may not make sense to build a costly IT infrastructure in house.

Successful IT professionals are not only technically savvy but also business savvy.

Best Practices for Using NFS Datastore on VMware

More companies are now deploying VMware with IP based shared storage (NAS). NAS storage is cheaper than Fiber Channel (SAN) storage because there is no separate Fiber Channel (FC) based network to maintain. More importantly, IP based storage performance and stability are now comparable with FC based storage.

Other advantages of using IP based storage, specifically NFS, are thin provisioning, de-duplication, and the ease-of-backup-and-restore of virtual machines and files on a virtual disk via array based snapshots. In addition, IP based storage is easier to maintain.

VMware published a whitepaper on the best practices for running VMware vSphere on Network Attached Storage (NAS) using NFS. Following the best practices in deploying an NFS based storage is very important to obtain a stable and optimized VMware environment. Here are the important things to consider:

On the network side, the local area network (LAN) on which the NFS traffic will run needs to be designed with availability, downtime-avoidance, isolation, and failover:

1. NFS traffic should be on a separate physical LAN, or at least on a separate VLAN.
2. Use private (non-routable) IP addresses. This will also address a security concern since NFS traffic is not encrypted and NFS is mounted with root privileges on the VMware host.
3. Use redundancy by teaming the NICs on the VMware host, configuring LACP protocol, and using two LAN switches.
4. Use jumbo frames.
5. Use 10GB Ethernet.

On the storage array side, the storage controller must be redundant, in case the primary one fails. In addition,

1. Configure the NFS exports to be persistent. (e.g. exportfs –p)
2. Install the VAAI and other plug-in tools from the storage vendor. For instance, NetApp has the Virtual Storage Console (VSC) plug-in that can be installed on the vCenter.
3. Refer to the storage vendor best practices guide. For instance, NetApp and EMC published their own best practice whitepapers for using NFS on VMware.

On the VMware hosts, the following configuration should be implemented:

1. Use the same datastore name across all hosts.
2. Select “No” for NIC Teaming failback option. If there is some intermittent behavior in the network, this will prevent the flip-flopping of NIC cards being used.
3. If you increase the maximum number of concurrent mount points (from the default of 8), also increase Net.TcpipHeapSize as well. For instance, if 32 mount points are used, increase tcpip.Heapsize to 30MB.
4. Set the following VMware High Availability options: (NFS heartbeats are used to determine if an NFS volume is still available.)
NFS. Hearbeat.Frequency=12

When configured properly, IP based storage, specifically NFS, provides a very solid storage platform for VMware.