In a world filled with uncertainty, ambiguity and vagueness, the one reality about which there is absolutely no doubt is that data will continue to grow unabated. A recent IDC survey states that user data and other unstructured data are growing at exponential rates. Also, due to compliance regulations, organizations are compelled to retain data for longer durations.
As the data grows, the number of NAS boxes in an organization to store this data also increases, and consequently so does the NAS data to backup. The backup window thus increases too. Here are some best practices to follow in order to reduce the NAS backup window and increase the NAS backup throughput.
Implement NDMP NAS backups
Almost all of the backup software solutions and NAS devices support network data management protocol (NDMP) backups. NDMP is a protocol designed to give high backup throughput of NAS data. There are multiple NDMP implementations available. In case there is a SAN in place along with an FC tape library, then the direct NDMP backup method should be used for the NAS backup. In this method the tape drives are zoned with the NAS device and NAS backup data travels over the SAN to the tape drive. This method ensures optimum NAS backup performance.
If a SAN is absent, use the local NDMP method wherein the backup device, i.e. tape drive, is directly attached to the NAS. Often, there could be multiple NAS systems in the environment. In such environments, use the remote NDMP method wherein the backup device is attached to a server and NAS devices backup over the LAN via NDMP to the backup device. To improve the throughput of NAS backups in remote NDMP backup implementations, use multiple servers connected to single or multiple backup devices.
Implement archiving solutions
Instead of backing up the same data repeatedly during full backups, consider implementing an archiving solution that archives the infrequently used data to the backup device. Now when the backup software initiates the full backup, the unchanged NAS backup data that has already been archived will not be backed up again. For example, one can apply a policy on the archiving software to stipulate that data that has not been modified for a period of one year should be archived to the backup device. Thus if, say, 10 TB of data meets this requirement, the backup window would reduce to that proportionate extent.
When implementing remote NDMP backups it is desirable to use a dedupe-enabled backup device. The dedupe ratios in such cases would be quite high, as there is a high probability of finding redundant data blocks in user data. The NAS backup performance levels would increase, accordingly.
Staging the NAS backup data from the disk-based device
Backup the NDMP data to disk-based devices to ensure high backup throughput. At a later stage the data can be moved to tape devices so as to ensure optimal usage of the disk-based devices.
Dedicated backup LAN/VLAN
If possible, a dedicated backup LAN or a separate VLAN should be configured for NDMP backups in order to isolate production traffic from NAS backup traffic and thus ensure optimum backup throughput. Also, the LAN network should have at least 1 Gigabit Ethernet connectivity between the NAS box and the backup device for optimum NAS backup throughput. In scenarios with the NAS backup larger than 1 TB, 1 Gigabit Ethernet links should be the minimum, and for even larger NAS backup in the 10 TB range, 10 Gigabit Ethernet links should be preferred.
Direct access recovery
Most backup software solutions provide for direct access recovery. For faster data recovery and individual file recovery, a direct access recovery implementation is preferable, and remains the best option available currently for NAS data recoveries.
Many of the NAS vendors offer specialized devices known as NDMP accelerators that are designed to improve the NAS backup throughput. Consider implementing NDMP accelerator devices in environments where the backup window is tight, and very high backup throughput is needed to meet the backup window requirements.
About the author: Anuj Sharma is an EMC Certified and NetApp accredited professional. Sharma has experience in handling implementation projects related to SAN, NAS and BURA. He also has to his credit several research papers published globally on SAN and BURA technologies.