| ARTICLES | September 2006 |
Since the beginning of time…
from cave paintings to computer data
SINCE the beginning of time, man has worked to record and preserve data. From the earliest cave paintings through to the modern day, creating a permanent record has been a quest – but today’s data deluge has created a set of challenges that previous generations could not even have guessed at. Data is the lifeblood of today’s organisations and the inability to access this data for whatever reason, directly impacts the bottom line.
For most organisations, the period for which they are willing to accept a loss of data access is a cost/risk analysis based on two major factors: the Recovery Point Objective (RPO) and the Recovery Time Objective (RTO). The RPO is basically how long ago the last backup was taken and RTO is how long it takes to restore backed up data.
It can be all too easy to fall into the mindset of thinking this is all about traditional tape backup solutions which despite technological advances, has not kept pace with the double challenges of escalating data volume and shrinking backup windows.
Retention challenges
There are a number of vendors who have solutions to solve the age-old data retention challenges. Each of these fits a market segment addressing particular customer requirements.
Snapshotting addresses the market which requires very tight RPOs and RTOs. Essentially, this process allows the contents of a disk to be ‘frozen’ and any changes made to the data written to another area of disk. As most activity in disk systems is data reads, the ‘write area’ of disk does not need to be large. Snapshots can be set to happen at pre-set time intervals, perhaps every ten minutes, half an hour or an hour.
When the time comes for the next Snapshot, both the original data and the newly written data are ‘frozen’ and a new ‘write area’ of disk allocated for changes to be written. The number of times this can happen can be pre-set so, for instance, twelve snapshots could be taken at hourly intervals. In this way a lost file or data could be recovered, within a 12-hour window with the data being recoverable at one-hour intervals. At the end of the 12-hour window, the oldest write area is merged with the original data and the cycle continues. This approach offers a level of granularity and operational transparency which is impossible to match using traditional tape backup techniques. The value proposition for resellers is that this is a proven technology which can use a customer’s existing disk types and offers a level of functionality beyond traditional backup systems based on a pricing system which scales with system implementation.
While Snapshotting provides a valuable solution for the headquarters operation in an organisation, managing the backup of data in a remote office can often be problematic. While this could be done directly by a tape system at the remote site, the processes, disciplines and skill sets may be lacking. Many organisations are now centralising their backup at their headquarters to not only save the expense of tape systems at each remote office but also to ensure that regulation and compliance requirements are met.
Centralising backup
Centralising backup creates a new challenge – how do you move large volumes of backup data over a slow WAN (Wide Area Network). Agentless online backup and recovery software is the answer. Not only is the backup data stored at the remote site for rapid restoration of lost data but it is also sent over the WAN to be backed up at the central site. When the next backup is invoked, because it has a record of the previous backup at the remote site, it only needs to send changes that have been made, over the WAN to the central site, thus reducing the impact of slow WAN speeds.
Even with this technique WAN speeds can still be too slow for significant backup data to be transferred in good time and that’s where the leading vendors have yet another embedded solution – compression. By compressing the data, the size of the WAN transfers can be reduced by four times or even more, speeding up the transfer time by the same amount.
WAN backup
Backing up over a WAN also introduces another concern for organisations – data security. Moving sensitive commercial data over a WAN creates the potential for interception. Choosing a solution that incorporates some of the most sophisticated encryption techniques commercially available today solves this issue.
Having provided effective solutions for both headquarters and remote office backup, there is one other area still left to consider – archiving. Archiving is often positioned as part of the family of backup techniques but it is much more of a distant cousin than a close relative. The significant difference between the two is that backup is primarily about the restoration of data to a known good point in time while archiving is about the long-term storage of unchanging data.
Optical media is one of the main storage media for long-term archiving because the stored data is unchangeable – making it suitable for legal submission as a true record. Most of the optical media that has traditionally been used, such as CDs and DVDs, suffered from limited data storage capacity making the number of platters required to archive any serious amount of data, excessive. As a result of ground-breaking research and development new optical media has been created specifically for serious archiving – Ultra Density Optical (UDO). UDO can store six times the data that DVD-based system can and as the technology develops this will soar to eighteen times. UDO has now been adopted by major industry players such as HP and Xerox, with the media second sourced by Sony.
The range of backup, restore and archive options offered today provide business with solution to meet the requirements of legal and regulatory compliance whilst still serving them well in to the future.
Zycko Ltd is exhibiting at Storage Expo 2006 the UK's largest and most important event dedicated to data storage, now in its 6th year, the show features a comprehensive free education programme, and over 90 exhibitors at the National Hall, Olympia, London from 18 - 19 October 2006 www.storage-expo.com
Zycko Ltd. Tel: +44 (0)1285 868 500; www.zycko.com
