On Wed, Nov 10, 2010 at 11:08:17AM +0300, Evgeniy Ivanov wrote: > On Wed, Nov 10, 2010 at 4:32 AM, 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*. Not to mention > > the significant security issues (e.g stale data exposure) that also > > occur even if the filesystem is not corrupted by the crash. IOWs, > > data=writeback is the "fast but I'll eat your data" option for ext3. > > > > So I recommend that nobody follows this path because it only leads > > to worse trouble down the road. Your best bet it to migrate away > > from ext3 to a filesystem that doesn't have such inherent ordering > > problems like ext4 or XFS.... > > Is it save to use "data=writeback" with ext4? I believe the same issues exist with data=writeback in ext4, but you probably should have an ext4 developer answer that question for certain. > At least are there security issues? > Why do you say, that fs can be corrupted? Metadata is still > journalled, so only data might be corrupted, but FS should still be > consistent. Data corruption is still a filesystem corruption. 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>