On Tue 28-05-13 22:39:18, jingguo yao wrote: > Documentation/filesystems/ext4.txt has the following sentence: > > This mode is the slowest except when data needs to be read from and > written to disk at the same time where it outperforms all others > modes. > > And the following link talks about it in more details. Can anybody give > the reason? > > http://www.ibm.com/developerworks/library/l-fs8/index.html#4 Not sure why exactly data=journal was faster in that workload. But generally data=journal is known to help if you have shortlived files which are then written only to the journal and deleted before they are copied to the final location on disk. Also it may help by penalizing the writer so that readers have better chance to do their work... Honza -- Jan Kara <jack@xxxxxxx> SUSE Labs, CR -- 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
