Log-structured file systems: There's one in every SSD [LWN.net]

Log-structured file systems: There's one in every SSD

Posted Sep 20, 2009 19:07 UTC (Sun) by cmccabe (guest, #60281)
Parent article: Log-structured file systems: There's one in every SSD

Excellent article, Val!

> Once every block in the device has been written at least once,
> the SSD is doomed to a worst case performance state in which its
> spare blocks are at a minimum and data must be moved each time a
> new block is rotated into use.

I wonder if the manufacturers include "extra" flash chips to get around this problem. For example, if the device had 1.1 GB of flash, but reported 1 GB, it would never run into the worst-case scenario.

Colin

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Log-structured file systems: There's one in every SSD

Posted Sep 20, 2009 23:37 UTC (Sun) by dlang (✭ supporter ✭, #313) [Link]

we know that they do include more flash than they report, but it still takes a significant amount of time to erase it, so the problem doesn't quite hit the worst-case scenerio, but it's still not pretty.