Posted Mar 6, 2013 18:23 UTC (Wed) by Tobu
In reply to: "cache drives"
Parent article: The conclusion of the 3.9 merge window
The small print on that page says it has 50% over-provisioning, so not visible outside of the SSD firmware. That must be there to compensate for the dataplex caching driver doing something not SSD-friendly, like heavy in-place rewriting (which would otherwise prevent the FTL from doing its work refreshing cells and spreading writes). bcache at least only writes whole erase blocks (1MB default bucket size), so it doesn't need that kind of overprovisioning.
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