One of the more interesting dynamics regarding storage these days is that as the volume of data being processed by organisations across the board continues to mount, the price of storage continues to fall.
As a consequence, even through the more traditional storage options are increasingly incapable of satisfying demand, the new offerings are ore suited to the needs of more business irrespective of their size.
So of what do these choices consist and how do they differ from more traditional storage models?
The first and most expensive of these new technologies is the storage area network (SAN), which according to experts, comprises an entire network dedicated to storage and is best suited to organisations running large databases.
“It works best where companies want very high performance and to really manage, their data resources deeply because it addresses data at the block level. The problem is that the investment in SAN technology is quite significant. It’s not got a particularly low entry point and you also have to buy a lot of new infrastructure,” explains John Hammond, commercial director at value added reseller, Logicalis Computing
Traditionally, SAN devices have been connected using the SCSI protocol over fibre channel, a gigabit speed networking technology, which, in cost terms, is out of the immediate reach of many companies, especially smaller firms.
Yet initial investment is but a small part of the overall issues that need to be taken into consideration, argues believes Sue Clarke, a senior analyst at Butler Group. “SANs are not simple systems. They’re complex and organisations will need third party help to set up at least some of it and then they may face a lack of internal resource to operate and manage it,” she explains.
A general shortage in IT personnel trained in the relevant SAN–related skills makes using SANs a non-trivial issue for the largest of companies; a situation exacerbated in those organisations without an IT department.
While this situation undoubtedly presents an opportunity for suppliers to provide value added services, it can also lead to difficulties in your buying process. That is to say, you may need to convince your finance directors that investing in a fairly significant capital infrastructure project is worthwhile.
“If you put in a new application, you can often say that the return on investment is this and you’ll get your money back in x number of months. But it can be more difficult to justify the expense of networked storage and especially more expensive SAN technology,” outlines Clarke. “The finance director is likely to say ‘our current storage is working now and disks are cheap so why don’t you just put another one in’. This means it’s necessary to put the case in terms that the business will understand such as networked storage will make it easier to do disaster recovery.”
The second category of networked storage technology, meanwhile, is network-attached storage (NAS). Unlike SANs, which comprise separate specialised networks, NAS consists of storage devices that can be plugged into a general-purpose IP-based local area network.
As a result, NAS systems are cheaper to set up and run than SAN-based ones, but, on the downside, are also slower. They are, however, quicker than more traditional direct-attached storage (DAS) and are also simpler to manage because the hard disks of which they comprise can be looked after from a central point.
Other advantages include higher levels of scalability, reliability and availability than DAS, which comprises a single storage device such as a tape drive, SCSI hard drive or on-board RAID array that is connected to an individual server.
A key problem with the DAS approach, however, is that, not only does it use a lot of CPU processing power, but each device has to be administered, maintained and backed up separately, which can cause you management headaches, particularly when large volumes of data are involved.
“Many organisations are starting to move away from DAS because of its lack of manageability as the volumes of data they have to manage keep growing. It’s about the complexity of managing that environment so we’re tending to see more consolidation, with people moving to bigger servers and networked storage alongside that,” says Clarke.
It would be unwise to infer though that DAS has had its day and is essentially yesterday’s technology. Explains Clarke “For example, you might not want an application handling sensitive financial information to be available on the wider network. So there’ll always be a need for some degree of DAS and small organisations are also unlikely to have the volumes of data necessary to justify a move to any form of networked storage.”
Similarly, NAS was considered by some as “the poor man’s SAN” when it first came out and regarded by the same, somewhat simplistically, as nothing more than something that bridged yesterday’s technology in DAS, and tomorrow’s in SAN. It is evident that NAS is now coming into its own, gaining increased recognition for its strengths of file- and data-sharing, areas in which SANs are weak.
Nonetheless, the technology is also ideal for those businesses that cannot afford big upfront investments. As Robin Burke, a vice president of research at Gartner, points out: “Anyone can plug and play an extra 500 GB or even a terabyte into the network and you don’t need dedicated IT staff to do it.”
This can lead to a number of business benefits. Now that the differences between the two networked storage technologies are now becoming less marked, it is becoming increasingly possible to get the best of both worlds.
Graham Titterington, a principle analyst at Ovum explains: “Networked storage is not a new concept and it’s been around for a few years now, but what is new is that the dividing line between SAN and NAS is getting more blurred. In the past, the two technologies were quite separate, but they’re now coming closer together.”
For example, the increased availability of SANs based on iSCSI, an IP version of the SCSI networking protocol, means that they are becoming cheaper to implement as organisations can use IP rather than expensive fibre channel networks to connect their storage devices together.
While adoption of such technology is still in the early stages, into the future, it is likely to prove a popular choice. “A SAN-over-IP is now an option for SMEs that could never have thought of introducing one if they had to put in fibre channel,” says Clarke. And there are added benefits in terms of staff, an issue as stated, has plagued SAN usage. “The use of IP networks in SANs is quite a new phenomenon. It’s largely about economy and ease of use, not least because it’s easier to find people with IP skills,” says Titterington.
But iSCSI has also begun to appear in the NAS world. The pioneer in this space was Network Appliance, which introduced both fibre channel and iSCSI support into its NAS devices to give them SAN-like qualities, although other vendors have since followed suit.
As to which types of organisation are using network storage technology, in all of its manifestations, however, this is mainly driven by the amount of stored data they are trying to tackle.
“As a rule of thumb, the bigger the organisation, the more likely adoption is, with SANs generally deployed in the data centre and NAS in mid-sized companies or at the departmental level. But that’s not the whole picture,” says Titterington.
For example, a media or publishing company generating huge amounts of data but employing only a small number of staff is more likely to introduce networked storage than a larger company doing manufacturing. The same applies to highly regulated industries such as financial services that may well be penalised if they don’t archive information.
“Another reason for deploying networked storage is to improve the backing up of data for disaster recovery and business continuity purposes. If you’ve got a lot of computers operating separately and you need to back them up every few minutes to ensure they’re up-to-date, it’s a real pain and very time-consuming to have to do it for each one individually,” Titterington says.
The bottom line for many organisations, however, is simply trying to keep on top of the 50% year-on-year increase in data needing to be stored and retrieved, and deploying the most suitable technology available to manage the complexity involved in doing so.
Despite this says Nigel Lambert, channel director at networking and storage distributor Zycko, take-up in by smaller concerns is still only at a fairly early stage, although he is seeing demand growing rapidly.
“If you take the top 5% of enterprises, adoption is pretty mature, but the sweet spot of the market is mid-sized companies and medium-to-large enterprises. While demand is across the board, network storage is a must-have now in local government, financial and insurance and professional services firms due to compliance issues,” he says.
Vendors complain that the main barrier to more widespread adoption at the moment is a lack of understanding of what networked storage is and what benefits it can bring. “There are a lot of network storage technologies and the technology itself is complex, which is very confusing for people. So one of our key jobs in the channel is to remove that confusion and help customers to move forward,” believes Lambert.
Yet among some dealers, confusion also exists. “Until recently, the networking and the storage channels have been very separate, with the IP community, for example, knowing very little about storage and the storage community knowing very little about IP. That is starting to change, however, with data networking channel in particular, starting to get more involved in the storage world,” Lambert says.
In the future, we will likely see the advent of technologies such as storage virtualisation, which involves putting a software layer over different physical storage assets to provide a single logical view, which makes them easier to manage.
The software also improves resource utilisation and eliminates vendor lock-in as it can run on any hardware, which means that different devices can be swapped out and replaced with minimum disruption.
And while this and other storage management software may still be relatively mature and at an early stage of adoption, it is likely to become progressively more valuable as storage complexity continues to grow in all sectors and for all organisations.