On Wed, Nov 10, 2010 at 07:59:10AM -0800, Linus Torvalds wrote: > On Tue, Nov 9, 2010 at 5:32 PM, Dave Chinner <david@xxxxxxxxxxxxx> wrote: > > > > Don't forget to mention data=writeback is not the default because if > > your system crashes or you lose power running in this mode it will > > *CORRUPT YOUR FILESYSTEM* and you *WILL LOSE DATA*. > > You will lose data even with data=ordered. All the data that didn't > get logged before the crash is lost anyway. > > So your argument is kind of dishonest. The thing is, if you have a > crash or power outage or whatever, the only data you can really rely > on is always going to be the data that you fsync'ed before the crash. > Everything else is just gravy. I crash kernels tens of times every day doing filesystem testing. With data=ordered I have not seen a corrupted root filesystem as a result of normal testing and crashing as long as I can remember. With data=writeback, I'll have corrupted root ext3 partitions in under a day. Hardly what I'd call stable or something you'd want to deploy in production. Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>