NFS (Network File System) is native to UNIX and Linux file systems. Because the NFS protocol is native to UNIX and Linux, it allows the file system to be provisioned thin instead of thick, with ISCSI or fiber channel. Provisioning LUN’s or datastores thin, allows the end user to efficiently manage their NAS capacity. Users have reported a 50% increase in both capacity and usable space.
Creating NFS datastores is a lot easier to attach to hosts than FC or ISCSI. There is no usage of HBA’s or fiber channel fabric, and all that needs to be created is a VMkernel for networking. NAS and SAN capacity can quickly become scarce if the end user can’t control the amount of storage being used, or if there are VM’s with over provisioned VMDK’s. NFS file systems can also be deduplicated, and not only are user’s saving space via thin provisioning, the VNX can track similar data and store only the changes to the file system.
EMC and VMware’s best practice is to use deduplication on NFS exports which house ISO’s, templates and other miscellaneous tools and applications. Enabling deduplication on file systems which house VMDK’s is not a best practice due to the fact that the VMDK’s will not compress. Automatic volume manager can also stripe the NFS volumes across multiple RAID groups (assuming their array was purchased with more than just 6 drives). This increases the I/O performance of the file system and VM. Along with AVM extending the datastores, this makes the file system transparent and beneficial to VMware (assuming you are adding drive to the file system). AVM will extend the file system to the next available empty volume, meaning if you add drives to the file systems you will be increasing the performance of your virtual machines.
Using VNX, Snapsure snapshots can be taken of the NFS snapshots and mounted anywhere in both physical and virtual environments. NFS Snapshots will allow you to mount production datastores in your virtual environment to use them for testing VM’s without affecting production data. Leveraging SnapSure will allow the end-user to keep up with certain RTO and RPO objectives. SnapSure can create 96 checkpoints and 16 writable snapshots per file system. Not to mention the ease of use Snapsure has over SnapView. Snapsure is configured at the file system level, just right-click the file system, select how many snapshots you need, add a schedule and you’re finished.
From my experience in the field the end-user finds this process much easier than SnapView or replication manager. Using VNX, NFS will also enable the user to replicate the file system to an offsite NS4-XXX without adding any additional networking hardware. VNX Replicator allows the user to mount file systems on other sites without affecting production machines. Users can replicate up to 1024 file systems, and 256 active sessions.
VNX datamovers can be purchased with 1 GB/s or 10 GB/s NICs. Depending on your existing infrastructure, the VNX can leverage LACP or ether channel trunks to increase the bandwidth and availability of your NFS file systems. LACP trunks enable the datamover to monitor and proactively reroute traffic from all available NIC’s in the Fail Safe Network, therefore increasing storage availability. It has been my experience interacting with customers who are leveraging 10GB on NFS, that they have seen a huge improvement in R/RW to disk and storage, as well as VMotion from datastore to datastore with up to 100% bandwidth and throughput.
Photo Credit: dcJohn