NAS is sometimes viewed as a challenge by enterprise shops if their intent is to use it as a target for disk-based backup. Two reasons often cited is that there is only a finite amount of storage capacity available on NAS and backup software does not handle out-of-space conditions on file systems very well. This causes failures in backup jobs as well as performance bottlenecks when multiple backup jobs are occurring . The use of grid storage architectures in products like the NEC HYDRAstor are helping to put some of these concerns to rest and making NAS a more practical option for use as a target for disk-based backup in enterprise shops.
Here are the typical concerns that enterprise shops have about using NAS as a backup target and how the HYDRAstor addresses them:
- Limited file system capacity
. Backup software and NAS systems are not always the best of friends when it comes to disk-based backup. While some backup software has the ability to manage out-of-space conditions on file systems, not every product does, so jobs can hang or abort unless an administrator manually intervenes. The HYDRAstor averts these situations by presenting to the backup software a file system that is essentially of infinite size (256 PB) and can be easily extended on the fly if/when such a need does become a reality. Not only is a 256 PB file system large enough to give even large enterprise shops sufficient headroom to meet their backup storage capacity needs into the foreseeable future, the HYDRAstor also deduplicates and compresses the data as it is stored to further alleviate storage capacity concerns.
Inability to scale storage capacity. The HYDRAstor does not just support one 256 PB file system but as many as administrators want to create. However it does not require that companies purchase all of that storage capacity at once but enables them to add it over time to the HYDRAstor configuration. In essence, the HYDRAstor is an extreme form of thin provisioning as it thinly provisions a 256 PB file system so it uses only as much storage capacity as backup data is stored to it. I call it extreme because the capacity in the HYDRAstor is available to any file system that needs it at any time across the entire HYDRAstor grid. Similarly, if the HYDRAstor itself starts to run out of storage capacity, it alerts the administrator so he/she can add more Storage Nodes to the HYDRAstor configuration. When additional capacity is added to the HYDRAstor grid, it becomes available for use to any of the file systems that need it without the need to allocate capacity to specific file systems.
Inability to scale performance. Everything about backups is performance intensive, especially when using disk as a backup target. The HYDRAstor must reserve some compute overhead for the file system itself; it needs to ingest multiple backup jobs at the same time; it needs to deduplicate and compress the incoming backup jobs; and, finally, it may need to recover and replicate data while these other functions are executing. Since all of this is occurring in an enterprise environment, it is conceivable that a NAS system may have inadequate performance to go around. The HYDRAstor's grid storage architecture addresses these concerns as well. Just as it offers Storage Nodes to scale storage capacity as companies need it, Accelerator Nodes that can also scale performance so companies can expand performance when they need it. Using this 2-tier grid architecture comprised of Accelerator and Storage
Nodes, companies can linearly scale the resources of the HYDRAstor to maintain performance as the system grows.
Enterprises are justified in their skepticism about using NAS as a disk-based target for backup. However the second release of HYDRAstor continues to alleviate some of these concerns. Not only is it a second generation product (which always helps to give enterprise shops more peace of mind) but it continues to make monitoring, managing and scaling capacity, performance or both on the HYDRAstor relatively pain free and simplistic events. And while features such as its 256 PB file systems have been part of HYDRAstor since its first release, when companies factor in its improved performance and higher capacity features coupled with what else the HYDRAstor already has to offer, HYDRAstor begins to present a compelling case for using NAS at the enterprise level for disk-based backup.
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