On Sun, Nov 07, 2010 at 07:50:13AM -0800, Linus Torvalds wrote: > On Sun, Nov 7, 2010 at 4:08 AM, Jens Axboe <axboe@xxxxxxxxx> wrote: > > > > As already mentioned, ext3 is just not a good choice for this sort of > > thing. Did you have atimes enabled? > > At least for ext3, more important than atimes is the "data=writeback" > setting. Especially since our atime default is sane these days (ie if > you don't specify anything, we end up using 'relatime'). > > If you compile your own kernel, answer "N" to the question > > Default to 'data=ordered' in ext3? > > at config time (CONFIG_EXT3_DEFAULTS_TO_ORDERED), or you can make sure > "data=writeback" is in the fstab (but I don't think everything honors > it for the root filesystem). 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.... 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>