Re: Sync option destroys flash!

From: linux
Date: Fri May 13 2005 - 21:44:47 EST


Alan the Hirsute spake unto the masses:
> All non-shite quality flash keys have an on media log structured file
> system and will take 100,000+ writes per sector or so. They decent ones
> also map out bad blocks and have spares. The "wear out the same sector"
> stuff is a myth except on ultra-crap devices.

I would have though so, but I can say from personal experience that
SanDisk brand CF cards respond to losing power during a write by producing
a bad sector. I had assumed that a sensible implementation would take
advantage of the out-of-place writing by doing a two-phase commit at
write time, so writes would be atomic.

Does anyone know of a CF manufacturer that *does* guarantee atomic writes?
Obviously, if power is lost during a write, it's not clear whether
I'll get the old or the new contents, but I want one or ther other and
not -EIO.

Given that SanDisk first developed the CompactFlash card, you'd think they'd
be a fairly reputable brand...
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