Race for space enters a virtualised world

It is possible – even easy – to put a terabyte of disk on an office user’s desktop. The sheer volume of data flying around today’s businesses approaches the ridiculous.

Fortunately, technologies in the data centre continue to evolve to help storage professionals stay on top of the situation, although, increasingly, storage needs may be driven by policy and politics more than by technology and capabilities.

‘The things you need to do to retrieve data are changing at their own pace, often at a frequency greater than the lifespan of the media holding the data, so you need to have a process in place,’ says Gartner research director Stanley Zaffos.

One increasingly significant trend is storage not as discrete pieces of media, but as a virtual pool of tiered capabilities, sorted by task or cost so that users appear to have their own storage area which is actually remote and centrally managed.

‘Storage virtualisation is a healthy thing, and now that it’s being moved to the network in appliances and switches, early feedback from customers is that it has increased use of available, paid-for storage,’ says Brian Garrett, industry analyst with Enterprise Strategy Group (ESG).

Major virtualisation projects probably still number in the thousands, in part because the software, middleware, and hardware vendors have yet to align with a unified virtualisation method. ‘Storage vendors are going to wait until they’re pushed,’ says Garrett.

Some of these suppliers still benefit from selling additional disks, even if installed disks are not full. But even without that integration, costs have come down – some experts claim that comparable storage area network (San) products are less than 10 per cent the price they were three years ago.

Some companies are already sold on the benefits and realities of virtualisation.

‘Large customers who have an investment in San, and have had two or three years running trillions of dollars per day through the equipment, understand the benefits and see San as a maturing market,’ says Michael Hughes, general manager of northern Europe for vendor McData. ‘They are now looking at how much guaranteed uptime there is, and they have an increased desire to make use of their storage fabric.’

Continuing to fuel interest in low-end and single-product virtualisation projects is iSCSI, the gigabit Ethernet-based San technology which offers distinct cost advantages over the conventional Fibrechannel San. ESG believes there are roughly 12,000 professional deployments of iSCSI.

‘It has great value in small businesses, some email applications, and departmental databases, but it’s still quite early,’ says Garrett. ‘Microsoft has bought iSCSI technology, they have a lot of skin in this game, and that has good implications for small businesses.’

Virtualisation walks hand in hand with tiered storage or so-called information asset management (IAM) disciplines. Once companies determine their high, medium, and low-value data assets, virtualisation makes it easier to create average cost pools of mixed-media storage to handle those records and files. The problem for IAM adherents is that the value of an individual piece of data, as well as an entire class of records, tends to fluctuate.

‘The difficulty here is not the infrastructure – a customer can get serial ATA disks, then iSCSI, then higher availability on 1-2GB and then 4GB or higher Sans. The difficulty is how do we recognise when data value has changed without going through a lot of manual administration?’ says Tom Clark, McData director of solutions and technologies.

The backup window remains a daunting challenge to storage planners, who must juggle a growing pool of storage against a shrinking off-peak period. Moving to disk-based, near-line backup can alleviate some of the speed concerns, but enterprise-grade capacity on disk is still an expensive prospect. The best advice? Back up smarter, not harder.

‘We encourage people to take a data management view – when they analyse their backup, most companies actually find that every night they’re backing up lots and lots of data that never changes,’ says Jim Spooner, principal storage consultant at Glasshouse Technologies. ‘When you get a wider view of your data and understand its requirements, the backup window situation improves.’

Some view the continuous data protection (CDP) approach as the best defence against the shrinking backup window. CDP views every change in data as an event to be recorded – crudely speaking, a progression of incremental backups occurring in real-time. ‘The idea of backup windows is replaced by that of recovery points,’ says Jim McDonald, chief technology officer of data protection specialists WysDM. But the expense of being able to record every data change to archive media, in terms of processor, network, and archive storage resources, can be considerable. ‘There is no simple solution – you could say CDP is the best technology now, but there are costs to implementation,’ says McDonald.

The matter of offsite backup storage has become a tricky one. In recent years the drive for disaster recovery considerations has been a strong force, pushing more tapes and even entire redundant server environments into the safety of underground bunkers. But data retrieval regulations now place a premium on the speed with which demanded records can be produced – making the efficiency of an offsite storage facility just as important as its impregnability.

‘We recommend doing a full-blown disaster recovery test once a year. It demonstrates that the service works, and their own processes as well,’ says Andy Maurice, head of consultancy for offsite storage provider Iron Mountain Europe.

Desktop and small business users will receive a boost to their backup capabilities when Blu-ray and HD-DVD drives, the two likely successors to DVD, reach mainstream prices later this year. In the data centre, such bare-media drives are often scoffed at, but optical storage continues to be extremely popular among organisations requiring a lifetime of customer records accessible with minimal delay, such as medical and financial institutions. As mainstream high-capacity blue laser optical devices raise awareness, and retrieval pressures continue to mount, optical could enjoy renewed relevance with a wider range of clients.

‘There is still a broad group of people who haven’t adopted optical for long-term archiving, but regulatory issues which make you keep data around for longer are making people consider optical technology,’ says Garrett. ‘If you just compare media prices it’s not a fair way of comparing an optical versus disk solution, because the total cost of ownership of these optical archives is really compelling.’

Many companies with a strong optical reliance had already migrated to the niche UDO blue laser optical format. Such companies tend to be unshakable in their long-term devotion to the media, and see similar attitudes from vendors.

‘We have 60GB UDO coming out soon, and we’re still selling 12-inch media to customers,’ says Steve Tongish, European marketing director for optical manufacturer Plasmon. ‘We sell things that are 15 years old and have not reached end-of-life in that sense, and that is the philosophy we take forward with UDO.’

No survey of the storage market is complete without a look at the seemingly inevitable disk for tape as a viable medium. As storage volumes skyrocket, disk and Raid technology prices plummet and blue laser optical formats move into the mainstream with HD-DVD and Blu-ray drives starting to hit the commodity markets, it could be a natural conclusion that tape’s days are numbered. Some of the evidence supports that perception.

‘We did some research just over a year ago on tape replacement realities, and in the very large corporate region we saw that as much as 40 per cent of tape budget and capacity is being replaced by disk-based capacity,’ says Garrett. ‘In large-scale tape libraries, growth is slowing, while bulk disk is growing phenomenally.’

Tape is not dead

But there is always a bright side for tape – its absolute indispensability and its uncanny ability to improve just in time to stave off obsolescence. ‘Tape is not going away in the near term or the long term. The cost advantages of tape are quite compelling, provided it is used as directed,’ says Garrett.

And those directives continue to push the capabilities upwards, with LTO4 tape technology, scheduled for release this year, promising 1.6Tb compressed on a cartridge with speeds of 240MB/s. ‘This market will continue to coexist by segment, with optical storage for home user and some backup use in the video market, while tape will be used for long-term shelf storage,’ says Taro Ikushima, commercial products manager at TDK.

With regulatory and business continuity concerns driving data archiving requirements, tape holds its value both as a short-term and a long-term backup medium. ‘Some data needs to be around for tens of years, and leaving that on spinning disk is incredibly expensive in the long-term. Once a tape is finished, it takes up very little power,’ says WysDM’s McDonald.

As requirements grow, the reliability and recoverability of information is increasingly a social and governmental problem – one inexorably tied to hardware and software, but which requires a more policy- and procedure-minded approach than ever before.

Gartner’s Zaffos says: ‘Look at some of the forces shaping the changes in infrastructure – the move to 24/7 data availability, the move to better product data, the need to be able to respond to changing regulatory requirements which dictate how much data has to be stored, for how long, and how much time you have to retrieve it.’

Case studies:

Backup and recovery at Pret a Manger

Business continuity at King Sturge LLP