one directory with 500 000 files (5-8mb each)

[Dan M]

On Mon, Jun 23, 2008 at 7:03 PM, Rob Mueller <robm at fastmail.fm> wrote:
> The biggest problem occurs if you store loop back filesytem dumps within a

I didn't store loopback fs dumps in a file, and still ended up with garbage.

> file. When it does a fsck it scans all the data, so it'll see what looks
> like filesystem metadata, even though it really was within a file.

This is why, again, that fsck is dumb.

>> 2 - Its reliablity for e-mail systems is AFAIK uncertain. e-mail
>
> And where do you get that belief from? reiserfs also has data=journal and
> data=ordered modes, which provide the same consistency guarantees as other
> filesystems with those modes. data=ordered has been the default mount mode
> for ages.

Just because it has data=ordered mode, it does not mean that it has
UFS metadata update semantics - atomicity. I simply don't know whether
it does or does not do the right thing, so at least to me that's
uncertain. If fsync returns early before all data is safely written to
the disk, then you can lose email during powerfail or crash.

In any case this is an MTA and FS discussion, and not web nginx discussion...

-- 
Dan