The mke2fs command will allow a subsequent -b option to override a pervious one. So something like this will work: mke2fs -t ext4 -b 4096 -b 2048 -b 1024 /tmp/foo.img 100 So you don't really need to do hacks with sed. Also, if MKFS_OPTIONS has a -b option, then you shouldn't need to do any -b overrides at all, since that probably means the person doing the xfstest run actually specified a block size directly for a Good Reason. We might want to issue a warning message if the block size specified by MKFS_OPTIONS doesn't match what the test file system uses, but that's more of a sanity check than anything else. Also, see my comments about dbsize; it might be a good idea if we want to do this sort of thing to refactor out a standard way of determining the block size of the test file system. Cheers, - Ted -- To unsubscribe from this list: send the line "unsubscribe fstests" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html