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The ledger process consists of the following steps:Step 1. Update the main ledger sheet top-line balances that are on the capacity side of the main ledger sheet. The top-line balance is calculated by adding all of the component capacities for the specific subsystems. The specific subsystems are tracked in separate tracking sheets and map to top-line ledger balances as the enterprise architecture dictates. The capacity columns are divided not only by technology, but also by other factors such as location or functional environment.
Step 2. Normalize the top-line balance for percent overhead. Many storage systems require a certain amount of overhead to run efficiently and can't be managed at 100% capacity. The percent overhead should be determined so that it will indicate the point at which new infrastructure is needed. The component aggregate sheet allows a business analyst to reference the source data if there's a concern that the percent overheads are too generous.
Step 3. Reconcile the ledger entries. Forecasted storage actions that have been executed or cancelled should be marked as completed and taken off the active forecasting ledger.
Step 4. Analyze the updated ledger. After the ledger has been updated, a storage infrastructure capacity forecasting meeting is held. Using the ledger's graphical output, the team determines what actions, if any, are required to address forecasted activities.
- Extending leases vs. buyouts of storage infrastructure
- Placing new or existing data on different storage performance tiers
- Backup and disaster recovery (DR) scenarios
- NAS vs. SAN scenarios
After the analysis and scenario assessments, the team recommends a best course of action to management. Because the ledger process has been initiated, the management review process has been considerably more collaborative because management is now provided with a set of high-quality and transparent options.
Step 5. Open ledger for general use. The ledger, like your checkbook, is to be used throughout the week. Steps 1 through 4 are intended for periodic baselining and reconciliation activities.
Step 6. Begin reconciliation. Close ledger for general use and return to Step 1.
This was first published in January 2010