Re: fsync reliability

Excerpts from Simon Riggs's message of jue abr 21 05:26:06 -0300 2011:

> ISTM that we can easily do this, since we preallocate WAL files during
> RemoveOldXlogFiles() and rarely extend the number of files.
> So it seems easily possible to fsync the pg_xlog directory at the end
> of RemoveOldXlogFiles(), which is mostly performed by the bgwriter
> anyway.
>
> It was also noted that "we've always expected the filesystem to take
> care of its own metadata"
> which isn't actually stated anywhere in the docs, AFAIK.
>
> Perhaps this is an irrelevant problem these days, but would it hurt to fix?

I don't think it's irrelevant (yet). Even Greg Smith's book suggests to
use ext2 for the WAL partition in extreme cases.

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Álvaro Herrera <alvherre(at)commandprompt(dot)com>
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