On Mon, Jul 20, 2009 at 07:04:03PM -0400, Valerie Aurora wrote: > On Mon, Jul 20, 2009 at 05:29:04PM -0400, Theodore Tso wrote: > > Here's a revised proposal for the KCONFIG text. > > > > Hopefully this is balanced about the two sides of the issue, without > > explicitly advocating for one choice versus another. > > > > What do people think? > > I think it's extremely accurate and detailed, but too long - people's > brains turn off after about the 15th line or so. Here's an attempt to > distill your description down and refer out to another document (which > one?) for people who want to learn more. Fair enough; I've created an external document here: http://ext4.wiki.kernel.org/index.php/Ext3_Data%3DOrdered_vs_Data%3DWriteback_mode Comments? > config EXT3_DEFAULTS_TO_ORDERED > bool "Default to 'data=ordered' in ext3" > depends on EXT3_FS > help > > If the mount options for an ext3 filesystem do not > include a journal mode, mount it in "data=ordered" mode. Let me give a try at this: The journal mode options for ext3 have different tradeoffs between when data is guaranteed to be on disk and performance. The use of "data=writeback" can cause unwritten data to appear in files after an system crash or power failure, which can be a security issue. However, "data=ordered" mode can also result in major performance problems, including seconds-long delays before an fsync() call returns. For details, see: http://ext4.wiki.kernel.org/index.php/Ext3_Data%3DOrdered_vs_Data%3DWriteback_mode If you have been historically happy with ext3's performance, data=ordered mode will be a safe choice and you should answer "y" here. If you understand the reliability and data privacy issues of data=writeback and are willing to make that trade off, answer "n". - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
