On Aug 30, 2007 12:12 -0700, Mingming Cao wrote: > On Thu, 2007-08-30 at 17:37 +0200, Valerie Clement wrote: > > This patch adds a new option -D <descriptor-size> to mkfs to allow creating > > ext4 filesystems with larger group descriptor size. > > > > By default, the group descriptor size is 32 bytes. > > To support 64-bit physical block numbers and thus to be able to use filesystems > > > 16TB, the group descriptor size must be increased to 64 bytes. > > Could you explain a bit more why we need this option? It seems to me we > could make the block group descriptor size to 64bytes whenever creating > a ext4 filesystem by default. Is there any case we need to create ext4 > with old 32 bytes block group descriptors? Because we will only have a single tool "mke2fs", and it should be able to format filesystems for all kernels. Also, it may be desirable to make the descriptor larger for whatever reason (e.g. testing some new feature). Cheers, Andreas -- Andreas Dilger Principal Software Engineer Cluster File Systems, Inc. - 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
