[gxti]

If I were writing a block provisioning system I would keep a map of what blocks have not yet been written to and always read zero for those blocks. Then the first time it is written, allocate a block that has already been zeroed out. This way I don't waste time and electricity zeroing entire volumes before they are allocated or after they are deleted because there is just one pool of same-sized blocks to draw from. Choosing the block size to strike a balance between allocation delay and cost of blanking is an exercise left to the reader.

[cloudsigma]

That's a possibility, the concern is the performance implications, particularly latency involved in operating such a system which needs to interrogate every data access. The question is whether such a system would have more of a performance hit than simply encrypting (with the added advantages that has anyway).

Best wishes,

Patrick