There's a lot more to backup than you thought

Which kind will you choose?

Science of appliances

HDS acquired Sepaton’s Virtuoso backup-to-disk deduplicating systems, which occupy this product category, as does Fujitsu’s Eternus CS8000, which uses Quantum-sourced deduplication and scales up to 22PB (before deduplication) by adding nodes to build multi-box resources.

This CS8000 can also manage the capacity of attached tape libraries, giving the sysadm flexibility in positioning backup data on disk, deduplicated disk or tape.

Where such capable and typically high-end systems are not needed then simpler backup to disk appliances with a scale-up architecture can appeal. Examples are Fujitus’s Eternus CS800 or EMC’s Data Domain Series. These can be combined with any backup software on the market.

Finally, if users focus on one backup software only, then an integrated appliance may offer greater simplicity. It will be easier to implement, operate and scale, but may lack the specialised abilities of the combined systems.

They offer backup and archive processes, with over-arching data management software providing a single interface and management resource.

For example, Fujitsu’s Eternus CS200c appliance features:

• CommVault Simpana backup/archive management software
• Local disk and/or SSD storage
• Deduplication for storage cost efficiency
• Support for physical and virtualised server data source systems
• Tape management features for archiving to tape

We could think of this as a three-way combination of backup media server, target backup-to-disk device and backup/archive data management software.

Planes, trains and automobiles

One reason for the plethora of backup devices and types is that the needs of data source devices are so different. To say that all need data protection is not that helpful.

As an illustration, the citizens of a country all have a common need to travel, but the modes of transport vary hugely, from walking, bicycles, cars and trains to ships, planes and even space shuttles. The moral is that you share a mode of travel, or backup, when you can and specialise when you must.

If we generalise we might envisage three main customer type needs:

• Small business system with little or no archive need
• Centralised combined backup and archive appliance with management software
• Consolidated enterprise systems with with mixed mainframe, Unix and x86 computing support and backup, archive, disk and tape storage environment

In vehicle delivery terms we could classify these as the panel van, the basic truck and the articulated lorry approach.

A small business’s needs could be satisfied by a simple and basic backup-to-disk deduplicating target. This could also meet the needs of larger enterprises' remote and branch offices, although these might be better served by smaller versions of more capable integrated backup/archive appliances that can communicate to the central data centre.

They can also, for example, deduplicate across the totality of the business’s backup data set, gaining better cost efficiency.

The consolidated enterprise need could be satisfied by all three kinds of backup appliance or by using the high-end systems and feeding a central system with data from remote and branch offices.

There will never be a single backup and archive system that meets all data protection needs, from those of small businesses to mid-level ones and global-scale enterprises and serving everything from mainframes to non-X86 Unix servers and commodity X86 servers, both physical and virtual.

Clouding the issue

Then there is the cloud, which we will consider only briefly here for reasons of space.

If you can use the public cloud then a starting approach would be to say that you need a gateway system to collect the backup data on your premises and then send it to the cloud.

As restoring anything but small files from the cloud takes a relatively long time you could envisage a backup appliance having cloud storage gateway functionality added to it. Recent restore needs are met by backup files on the appliance, and are hence fast. Restores of older data that is less often needed could come from the cloud.

In fact, we could do a neat split and say backup is local and archiving is in the cloud, with Amazon or Azure substituting for an on-premises tape library.

Holding backup data on the appliance on premises might better suit your need for secure storage of sensitive data, especially where there are geographic restrictions on its dispersal.

As we have seen, there are always specialised options for backup, as well as seductive all-embracing alternatives that have the appeal of simplicity, such as back up and archive everything in the cloud.

Be suspicious. In this area one size almost never, ever fits all. Use common backup and archive services when you can, when they make sense, and not to excess. Specialise when it makes sense but there is no need to hyper-specialise.

A central backup and archiving appliance core will generally make sense, with the cloud reserved for potential archiving and socialised backup systems for the corner cases that are outside the appliance corral.®