On 2013-01-22, at 4:50 PM, Bradley C. Kuszmaul wrote: > Thanks, this has been a very helpful thread. > > How do I determine and control whether a file is extent-based? You can use "lsattr" on the file, and look for the "e" attribute. This should be standard for any ext4-formatted filesystem. For filesystems upgraded from ext3, you need to "tune2fs -O extents" to enable this feature. Cheers, Andreas > On Tue, Jan 22, 2013 at 11:20 AM, Zheng Liu <gnehzuil.liu@xxxxxxxxx> wrote: >> Ext4 file system supports hole punching. But until now only extent-based >> file supports it. As far as I know, redhat distributions don't support >> hole punching. You can find a sample program from e2fsprogs which is in >> $e2fsprogs/conrib/fallocate.c. The latest fallocate(1) in util-linux >> also can be as a demo. > -- > 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 -- 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