Hmmm.. I guess that you can try to read this file using
$ hadoop fs -cat <file-with-corrupt-replica> to detect that
When reading a file its checksums are calculated and compared to checksums
that were calculated during a write operation. If verification fails, NN is
notified about the corrupt replica and you will fetch a different replica
from another DN to read that file.
2013/12/12 ch huang <[EMAIL PROTECTED]>
> what is the sample way to corrupt a replica of a block ,i opened a
> replica data file ,and delete a line,than use fsck ,nothing corrupt,
> should the DN be restarted?