On Thu, 2007-08-30 at 14:51 -0600, Andreas Dilger wrote: > 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. I agree. I was wondering why not make the 64bytes block group descriptor for ext4 as default. So by default we don't need to specify the size when creating ext4 fs. > Also, it may be desirable to > make the descriptor larger for whatever reason (e.g. testing some new > feature). > Okay, that could be useful for ext4. Don't feel ext2/3 needs that option. Regards, Mingming - 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
