Hi, [this is on rawhide: mke2fs 1.41.4 (27-Jan-2009) Using EXT2FS Library version 1.41.4 ] FWIW, I was trying to create an ext4 file system with more than 2^32 blocks to demonstrate a parted bug fix, but with the particular device I was using, I couldn't even create one with 2^31-1 blocks. When I try to create an ext4 file system specifying both block size and the number of blocks, the size of the underlying device should not matter, as long as it is large enough. However, when the underlying device too large, it fails like this: Set-up: Create a 10TB sparse device called /dev/mapper/s1 with /dev/sdb6 (just ~20GB) for backing store: N=$(echo '10*2*1024^3'|bc) echo "0 $N zero" | dmsetup create zero1 echo "0 $N snapshot /dev/mapper/zero1 /dev/sdb6 p 128" | dmsetup create s1 Try to create an ext4 file system with 2^31-1 1024-byte blocks: (note that I specify an explicit number of blocks) # mkfs.ext4 -b 1024 /dev/mapper/s1 $(echo '2*1024^3-1'|bc|tee /dev/tty) 2147483647 mke2fs 1.41.4 (27-Jan-2009) mkfs.ext4: Size of device /dev/mapper/s1 too big to be expressed in 32 bits using a blocksize of 4096. [Exit 1] I can understand failing like that when the "blocks-count" argument is omitted, because then we're asking mkfs.ext4 to use the entire device. Regards, Jim PS. let me know if you'd like a BZ for this, and I'll fill out the form -- 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