DDP’s are Ethernet based SAN systems which utilize the AVFS/iSCSI protocol. DDP drives behave the same as local drives with no latency or lag unlike some NAS systems. Network Attached Storage Systems (NAS) understand files and metadata and provide both storage and file-system. SAN storage systems only understand block data, leaving file-systems concerns to the client computer. Because NAS systems are file aware, it operates at a higher layer and therefore introduces more latency into the read/write process. The NAS appears to the client computer as a File Server requiring the client to map a network drive to share, where as a SAN disk presents itself to the client as a local disk allowing the client to deal with the file-system.
SAN & NAS
Because SAN storage operates at a lower layer it is substantially faster. For years the question has been: what to use, SAN or NAS? For many companies, the answer is both. While it is not a hard and fast rule, many companies use SAN for their database and e-mail applications and NAS for file storage. However, with the introduction of Ardis Technologies AVFS/iSCSI system companies can now use SAN with NAS simplicity and functionality. This Ardis Virtual File System combines the performance benefits of the iSCSI SAN protocol with the NAS intelligence using a single Ethernet network.
The iSCSI protocol has emerged as a popular alternative to Fibre Channel for block based storage area networking. Over the past two years, the adoption of iSCSI in production systems in companies of all sizes and industries has grown dramatically. AVFS uses the iSCSI protocol instead of Fibre Channel to accelerate data access. Unlike a FC SAN, AVFS works over a single Ethernet infrastructure carrying SCSI commands over the IP network allowing data transfers over intranets and over long distances.
Therefore Ardis Technologies believes that AVFS will ultimately address a much greater market providing SAN level performance with NAS level intelligence over a unified storage network.