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An unexpected perf feature
LWN.net Weekly Edition for May 16, 2013
A look at the PyPy 2.0 release
PostgreSQL 9.3 beta: Federated databases and more
LWN.net Weekly Edition for May 9, 2013
XFS: the filesystem of the future?
Posted Jan 26, 2012 10:53 UTC (Thu) by mpr22 (subscriber, #60784)
Posted Jan 26, 2012 18:41 UTC (Thu) by nix (subscriber, #2304)
Posted Jan 27, 2012 1:18 UTC (Fri) by dgc (subscriber, #6611)
Right and wrong.
The NFSv3 server is stateless, but the NFSv4 server is stateful to support functionality like file delegations to clients. Such functioanlity may require storing per-file state. e.g. so that the server can revoke a file delegation from a client when another client wants to access it.
Posted Jan 27, 2012 22:01 UTC (Fri) by nix (subscriber, #2304)
Posted Jan 27, 2012 1:12 UTC (Fri) by dgc (subscriber, #6611)
Because NFSv4 requires certain functionality from the underlying filesystem to be able to detect that a file has changed. This has to be valid across NFS server restarts (e.g. power off/on) so needs to be stored in stable storage. i.e. in the underlying filesystem. ext4 already has this functionality as it's on-disk format was changed at about the same time the NFSv4 functionality was introduced. Now that we are doing a major XFS format change, we can add this functionality as well.
Posted Jan 27, 2012 14:38 UTC (Fri) by bfields (subscriber, #19510)
Posted Jan 29, 2012 0:58 UTC (Sun) by sbergman27 (guest, #10767)
Posted Jan 29, 2012 2:32 UTC (Sun) by jrn (subscriber, #64214)
Posted Jan 29, 2012 4:15 UTC (Sun) by sbergman27 (guest, #10767)
Posted Jan 29, 2012 10:49 UTC (Sun) by nix (subscriber, #2304)
Posted Jan 29, 2012 23:14 UTC (Sun) by sbergman27 (guest, #10767)
Perhaps. I've spent enough time refuting baseless conspiracy theories that I am not about to promote one. I fear that I let myself become a bit of an Ext4 cheerleader, there.
Not intended. As I'm keenly interested in Ext4, Btrfs, and XFS. Clearly, all three of those have parts to play in the coming years. That Ext4 happens to be at center stage now should not detract from the fact that the trio is a team.
That's the message which I would like to convey.
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