On Jun 06, 2007 14:18 +0100, Mark Knibbs wrote: > This is a follow-up to my previous message. The bug is also present in > ext3, and applies to partitions with 2K blocks and (at least in part) to > those with 4K blocks. There is also another issue, which may well be a bug > in e2fsck. Could you please clarify what the particular defect is that you are looking at? Presumably it is not just that there is an upper limit on the size of a file? > For partitions with 2K blocks the maximum file size is 275,415,851,008 > bytes; changing the seek= argument in the dd examples to 275415851007 & > 275415851008 gives similar results. > > The maximum file size on partitions with 4K blocks is 2,196,875,759,616 > bytes, so I tested using dd with seek=2196875759615 & 2196875759616. With > 4K blocks there don't seem to be any problems with warnings in dmesg > output, or fsck. The only bug (or what I think is a bug) is that > dd if=/dev/zero of=test.bin bs=1 count=1 seek=2196875759616 > causes the file size to show as 2196875759616, but it shouldn't since no > actual write took place. The reason for this limitation is due to indirect block limits in the ext2/3 file layout. In ext4 it is theoretically possible to have files up to 2^60 bytes in size, because the extent format handles 2^48-bit block numbers, and the inode has an extra 16 bits to store the high part of the block count. > If instead you do > dd if=/dev/zero of=test.bin bs=1 count=1 seek=17247252479 > (which should work okay, since the maximum file size is 17247252480) then > fsck -f gives a strange message: > "Inode 6073, i_size is 17247252480, should be 17247252480. Fix<y>?" > Even if you say yes to "fix" it, repeatedly running fsck always asks that > question. This is definitely a bug... 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
