Buying a tape library is similar to ordering a new company car; there’s a huge of choice of vendors and devices, and now IT managers also have to consider wider pressures such as environmental impact and additional costs.
But, the key question for selecting your next tape library is ‘should it be physical or virtual?’
For the most part, virtual tape is the natural decision because it’s fast, easy to manage and relatively green. Virtual tape libraries (VTL) offer many benefits over the physical libraries that have traditionally dominated the market.
Firstly, the elimination of any physical element increases the appliance’s reliability and removes the significant time delay that an automated system incurs to find a cartridge.
The result is lightning fast restores and less frustration with tape recall. Also, the reduced footprint allows IT mangers to fill the free floor space with further hardware to support business growth.
There are, however, some important considerations that IT managers need to take into account before making their next tape decision.
While VTLs allow IT managers to create as many tape devices as they need without the cost factor of physical tape, they need to be wary of back up application vendors who are now licensing by capacity to compensate for this.
Also, if an organisation has a requirement to send media offsite cheaply, physical tape offers obvious benefits. However, IT managers shouldn’t dismiss virtual backups on this strength.
In fact, VTLs can be set up to be replicated offsite fairly simply, although this may have an effect on the capex and opex costs for the solution because of the requirement for a second VTL located off site.
Despite the additional cost, offsite tape replication is useful for business continuity purposes, so it’s something that most businesses should consider, because a single VTL solution will always be at more risk in the event of a failure.
Physical tape may step back into the design of a single VTL, to offer protection as a second copy or perhaps for cost and space reasons.
There are two ways to manage the copy from VTL to physical tape: by the VTL itself (if supported), or by the backup application. The benefit comes either when the VTL fails (where virtual tape recall is not possible) or when there is a replacement of the VTL to a new vendor and the backup application is unaware of the association between the VTL and tape copies.
For many businesses today, the most obvious choice for tape back up is to go virtual. To get the most out of the VTL, businesses need to make sure they select the right solution for their environment and have a mature plan for the design and implementation as well as ongoing management strategy to minimise risk and pitfalls.
VTLs have obvious advantages over physical tape, but if IT managers get it wrong, it’s far less forgiving than physical tape.
Hywel Matthews is a Technical Consultant at GlassHouse Technologies. GHT is a global provider of IT infrastructure services enabling organisations to consolidate, virtualise and manage their IT environments
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