ext4 vs ext3 with mongodb

Oded Maimon

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Dec 5, 2010, 6:28:32 AM12/5/10

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hi,
it seams that because mongodb uses memory mapped files anyway, using
ext4 will be better than ext3 for mongodb.
do you recommend using ext4 instead of ext3?

thanks,
Oded.

Andreas Jung

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Dec 5, 2010, 6:32:44 AM12/5/10

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Often discussed....

http://www.slideshare.net/mongodb/deployment-strategy

In particular I can not see how the usage of memory mapped files
with ext3 is different from ext4. The major advantage of ext4 over ext3
affects the pre-allocation of new database files.

- -aj

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Tim Hawkins

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Dec 5, 2010, 6:51:22 AM12/5/10

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ext4 shows some issues with certain disk work patterns, the sqlite community spotted this early on.

http://phoronix-test-suite.com/pipermail/trondheim-pts_phoronix-test-suite.com/2009-March/000101.html

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Markus Gattol

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Dec 5, 2010, 7:56:18 AM12/5/10

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As Andreas already indicated, it's file preallocation that's more
efficient, especially the fact that ext4 has posix_fallocate.
Have a look at http://www.markus-gattol.name/ws/mongodb.html#filesystem

Oded Maimon

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Dec 5, 2010, 10:37:13 AM12/5/10

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that also what i was thinking...

On Dec 5, 1:32 pm, Andreas Jung <li...@zopyx.com> wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> Oded Maimon wrote:
> > hi,
> > it seams that because mongodb uses memory mapped files anyway, using
> > ext4 will be better than ext3 for mongodb.
> > do you recommend using ext4 instead of ext3?
>
> Often discussed....
>
> http://www.slideshare.net/mongodb/deployment-strategy
>
> In particular I can not see how the usage of memory mapped files
> with ext3 is different from ext4. The major advantage of ext4 over ext3
> affects the pre-allocation of new database files.
>
> - -aj
>
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v1.4.11 (Darwin)

> Comment: Using GnuPG with Mozilla -http://enigmail.mozdev.org/

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>

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