I on the virtual machine with a single node of the hadoop pseudo-distributed, has been good, I don't know reason of emerged:

WARNING: There are about 12 missing blocks. Both Please check the log or run FSCK.
I closed after the hadoop, reopen goes something like this:

Cluster the Summary
Safe mode is ON. The reported blocks is only 1 but The threshold is 0.9990 and The total blocks 13. Safe mode will be turned off automatically.
38 files and directories, 13 blocks.=51 total Heap Size is 23.69 MB/966.69 MB (2%)

Such a question, I know this is I block piece is missing, the system has been in safe mode, although you can turn off safe mode, but I'd like to know how I can recover my lost bio data, because I don't have downtime, the namenode can merge fsimage and editors. But how to do??

Dear Daniel, to help the younger brother!!!!! Thank you,