Forecasting your Datacenter Storage Requirements.

Approach 1: Simple MathematicsTake what you already have (x)Multiply that by a reasonable guess (y)Multiply that by however long you plan to try and keep your job (z)Simple:X x Y x Z = probably not good enough for the CFO.

Approach 2:DelegateAsk each administrative team to investigate the data they are responsible for. (Apps, DB, Messaging, Unix, Intel, Storage etc…)Have them enter that data into a spreadsheet.Collate that information.Multiply it by last years growth rate.Do it all again very quickly because you’re now out of date.

The difficultyTypically most organisations measure storage at the front end.Couple this with a typically loose data management strategy.Add in an ever changing data retention target.And you achieve…. an almost impossible objective.

So why even try?The cost of storage is now typically the highest of most IT budgets.Data storage requirements are growing.IT budgets are not.You will enable the business to predict costs accurately.You will be able to enable changes in policy that have a direct impact on costs.You will be able to prove that more budget is a necessity and not simply to improve your budget holding status.

What to measure & Why

One other small factor:80% of data stored is off-line.Off-line Storage media (tiers) varies greatly in cost.Off-line data storage is most affected by policy decisions.Off-line Data storage is subject to the most change in retention.ReplicatedMigrated Email ArchiveNear-line Recovery CopyDe-DupeArchiveDev / UATBackupReplicated SnapshotOff-site DROn-Site DRApplication Copy

An example of the off-line impact.Disk 2InformationObjectInformationObjectInformationObjectInformationObjectInformationObjectApplication1Weekly BackupWeekly BackupWeekly BackupArchiveArchiveWeekly BackupDisk 1Weekly Backup144Archive TierArchive Tier1TapeMonthly BackupYearly BackupMonthly BackupYearly BackupMonthly BackupYearly Backup123+TOTAL Copies54+Monthly BackupYearly BackupMonthly BackupYearly BackupMonthly BackupYearly Backup123+Offline TierWeekly BackupMonthly BackupYearly BackupWeekly BackupMonthly BackupYearly BackupWeekly BackupMonthly BackupYearly Backup16123+

So, you’re going to need a strategy.You can only do this once you’ve an accurate measure of your estate (front and back).You can only do this once you have a view of your current data management policies (for all applications and file services)You can only make effective predictions once the business tells you what it needs to retain and for how long.And then you have to be able to model these requirements as they change.

BewareYou may want to change your hardware solutions moving forward.You will need to change your tiering model based upon changing business requirements.Your analysis must be inclusive of data that no longer resides on your site.Account for predicted programs and projects.Account for seasonal fluctuations.

So, to summarize.Business policies not IT policies will ultimately define your storage capacity requirements.Data evaluation programA reporting mechanism that caters for on-line and off-line reporting combined is a necessity.The ability to predict and trend based on policy change and current volumes (front and back) puts you in a very strong position to plan your future storage requirements.

Thank You