On Mon, Jul 20, 2009 at 10:00:50PM -0400, Theodore Tso wrote: > On Mon, Jul 20, 2009 at 07:04:03PM -0400, Valerie Aurora wrote: > > > > 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? Nice! > > 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". This is great. Ship it! -VAL -- 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
