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0 pointsmasklinn12y ago0 comments

It's not sync() which is the problem. A correctly implemented `sync` should flush all writes to permanent storage before returning.

The issue here is storage devices may lie about it[0]. The 2s sleep is problematic, but IIRC devices don't (and have no way to, and would not anyway) report when the data is actually written to permanent storage, so you can't do much besides waiting a bit and hoping for the best.

[0] http://www.sqlite.org/howtocorrupt.html

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2 comments · 1 top-level

JoshTriplett12y ago· 1 in thread

Storage devices actually do have several ways of reporting when data is permanently stored, and Linux makes use of them. However, some storage device manufacturers found that if they lied and claimed data was permanently stored when it wasn't quite yet, they got better benchmark results.

masklinnOP12y ago

> Storage devices actually do have several ways of reporting when data is permanently stored

Which `sync` uses. My comment was probably unclear, but the point I was trying to make is if they're lying to sync they're probably not going to provide other accurate ways to get the information.

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