Adopting a progressive or perpetual incremental backup strategy using Tivoli Storage Manager (TSM) is a fundamental concept users must accept to fully exploit the architecture. Despite its power, flexibility, and ability to automate cumbersome media management, storage administrators will often resist changing existing backup methods (e.g. weekly full backups) because TSM is a ‘black box’ that must be trusted completely. Despite the perils of TSM complexity, not embracing progressive incremental backups will invariably lead to excessively large databases which are wasteful and will negatively impact performance and costs.
The Wikibon Peer Incite exploring SaskEnergy’s challenges implementing TSM underscores the need for careful planning with regard to embracing progressive incremental backup strategies. TSM is indeed powerful by its very nature because it can be tailored to business requirements.
For example, in the case of SaskEnergy, accommodating a five year blanket retention policy and enabling specialized workarounds for Notes and other applications requires substantial planning and TSM domain expertise. Further complicating the situation at SaskEnergy is a long blanket retention policy mandated by the organization. This type of policy should be avoided if possible with TSM as it will overtax the backup application by unnecessarily backing up data that doesn’t need to be protected.
TSM’s flexibility is also a two-edged sword. For example, TSM can enable customers to accommodate backups for applications with special requirements (e.g. email or other database applications) that need to be available on a 24 X 7 basis. However users should be aware that this capability will require enabling and configuring additional TSM modules, requiring further planning and technical expertise.
The best advice with any IT implementation is where possible, keep it simple. This old adage holds true with TSM as applied to backup and archiving but is often easier said than done.
Action Item: These examples and the SaskEnergy Peer Incite demonstrate that TSM is powerful but extremely complex. Prior to implementing a perpetual incremental backup and archiving strategy using Tivoli, users should acquire deep TSM expertise and insist that capability exists as a pre-requisite of assuming responsibility for the project. Having a basic understanding of generic software and backup environments is not sufficient to succeed with TSM in this context.
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