Disk archives at the cost of tape
Providing actual cost per GB numbers would probably be the easiest way to demonstrate how close disk archives can come to the cost per GB for tape archives. Unfortunately we cannot just throw our list prices in the open. So although we do not believe tape will disappear and we are making a case for different active archive architectures, here is an attempt to explain why and how disk archives can be more attractive than tape archives from a TCO point of view.
An accurate TCO analysis of a complete HSM tape solution should take into account the servers (MetaData HA servers, Data Movers, NFS/CIFS gateways), the Fibre Channel redundant switches, FC tier 1 disk cache, etc. Add to this, the cost of HSM software licenses at $200-500/TB, and you eliminate most of the cost benefit of tape when compared to an AmpliStor solution. For an accurate non-HSM TCO, one needs to include the cost of backup or archive software, backup servers, etc., which again are overall as or more expensive than tape libraries. Also, tape library costs are only part of the whole, and the Active Archive Alliance’s (AAA) position that "disk is 15 times more costly than tape and uses 200 times more energy" for active archive is based on old and incomplete information: the AAA uses 5+ year old papers (Clipper Group), out of date disk pricing, and projects tape costs using the largest libraries only.
It is true that for the largest tape libraries, say over 10PB, the cost for two copies on tape is in the $200-300/TB range, uncompressed. If the data compresses, they are still untouchable. And, if they have already paid for the large libraries, then they will just point to the media cost, which is more like $50/TB. But for the majority of installed libraries in both backup and active archive, these libraries will cost from $450 to $800/TB for two copies across two libraries in separate datacenters. AmpliStor can go well below that cost. Any enterprise facing replacement of old tape libraries and renewing costly archive or HSM software licenses, will find the AmpliStor value proposition compelling.
At Amplidata we are merging the disk-based object store and eliminating at least a majority of the cost for libraries and software licensing for the tape tier, assuming a geo-spread configuration. Other less durable storage can't say that, as users need to keep the full two copies on tape (if they have a DR strategy). This is exactly what resonates with our customers: eliminating the need for tape or replicated high-end disk systems.
So while we don’t advocate moving away from tape altogether, our customers could do so. Our exact messaging on this is: “The AmpliStor system delivers such high levels of data durability (ten 9s, fifteen 9s – or beyond) that it can actually consolidate multiple existing tiers of storage. Typically customers deploy these multiple tiers to provide assurance for data durability: tier 1 (disk) + tier 2 (disk), or tier 2 (disk) + tier 3 (tape), or multiple copies on tape. With AmpliStor, a single instance of data provides much higher durability, thereby leading to tremendous savings on both capital and operational costs. AmpliStor can even come close to the TCO of two copies on tape, while providing the convenience, management ease and accessibility of disk, along with scalable, multi-gigabyte throughput.”