Proposed Disk Array With 99.999% Availablity For 4 Years, Sans Maintenance

Thorfinn.au writes with this paper from four researchers (Jehan-François Pâris, Ahmed Amer, Darrell D. E. Long, and Thomas Schwarz, S. J.), with an interesting approach to long-term, fault-tolerant storage: As the prices of magnetic storage continue to decrease, the cost of replacing failed disks becomes increasingly dominated by the cost of the service call itself. We propose to eliminate these calls by building disk arrays that contain enough spare disks to operate without any human intervention during their whole lifetime. To evaluate the feasibility of this approach, we have simulated the behaviour of two-dimensional disk arrays with N parity disks and N(N – 1)/2 data disks under realistic failure and repair assumptions. Our conclusion is that having N(N + 1)/2 spare disks is more than enough to achieve a 99.999 percent probability of not losing data over four years. We observe that the same objectives cannot be reached with RAID level 6 organizations and would require RAID stripes that could tolerate triple disk failures.

Comments

Re:Power Costs

[Sloppy]

This is how we're going bring our keepers to their knees, and eventually break out of the Matrix. We spend imaginary money on imaginary storage and then put all sorts of high-entropy stuff on it and run calculations to verify that it's really working, but they have to spend actually real resources, to emulate it.