请告诉我下面的错误代表什么意思!

draco301

# dd if=/dev/rmt0 bs=128k count=1 |wc -c\r\n1+0 records in.\r\n1+0 records out.\r\n  131072\r\n# chdev -l rmt0 -a block_size=512\r\nrmt0 changed\r\n# tar tvf /dev/rmt0\r\ntar: 0511-169 A directory checksum error on media; -266881297 not equal to 30236.\r\n# tar -tvf /dev/rmt0\r\ntar: 0511-169 A directory checksum error on media; -266881297 not equal to 30236.\r\n# tctl -f /dev/rmt0 rewind\r\n# tar tvf /dev/rmt0\r\ntar: 0511-169 A directory checksum error on media; -266881297 not equal to 30236.\r\n#

jxufe_legendxj

dd   bs=128k\r\nchdev block_size=512 byte\r\nbs<>block_size