As we seek to constrain and control the explosion in data growth is deletion of data and reclamation of storage an economically viable methodology?
I’ve seen a few articles over the past 18 months who calculate that this does not really make sense; if the cost of work required to reclaim that storage, then it does not make sense to do so. I remember looking at the cost of SanScreen when it was an independent company, their big sell was that it paid for itself in identifying orphaned storage and reclaiming that; unfortunately, it didn’t.
But does that mean that carrying out this sort of exercise is not worth doing? My answer to that is No! The benefits to good data management stretch beyond the economic benefits of reclaiming storage and more effective use of your storage estate.
If you never carry out this sort of exercise, you have resigned yourself to uncontrolled data growth; you have given up. Giving up is never a good idea even in the face of what feels like an unstemmable tide; you do not need to sit like Cnut and try to stop the tide coming in but you can slow it and take a greater degree of control.
This sort of exercise can be important in understanding the data that you are storing and understanding its value. And interestingly enough, you might actually want to delete valuable data for a whole variety of reasons.
You need to understand the legal status and value of the data; email in a legal discovery situation is the classic answer, if you have the data, you can be asked to produce it. This can be extremely costly and can be even more costly if you discover that you can produce data at a later date when you have said you can’t.
Those orphaned luns in your SAN, do you know whether or not, they contain legally sensitive data? Those home-directories of ex-employees, is there sensitive data stored there? The unmounted file-system on a server which has never been destroyed?
It is also important to understand the impact of the entire estate of keeping everything for ever; what is the impact on your back-up/recovery strategies? What is the impact on the system refresh and data migration in five years time? Do you only carry out this exercise when you are refreshing? If so, you are probably going to put back your migration strategy back a number of months and you could end up paying additional maintenance for longer.
There are many other consequences to a laissez-faire approach to data management; don’t just accept that data grows forever without bounds. Don’t listen to storage vendors who claim that it is cheaper to simply grow the estate but understand it is more than a short-term cost issue.
No, good data management including storage reclamation needs to become part of the day-to-day workload of the Data Management team.