Exception in thread "Lucene Merge Thread #3" MergePolicy$MergeException: java.io.IOException: Data error (cyclic redundancy check)

[liat oren]

Hi All,
I got the following error while trying to optimize index sized 31 GB:
Exception in thread "Lucene Merge Thread #3"
P.Lucene.Expert.index.MergePolicy$MergeException: java.io.IOException: Data
error (cyclic redundancy check)
        at
P.Lucene.Expert.index.ConcurrentMergeScheduler.handleMergeException(ConcurrentMergeScheduler.java:369)
        at
P.Lucene.Expert.index.ConcurrentMergeScheduler$MergeThread.run(ConcurrentMergeScheduler.java:338)
Caused by: java.io.IOException: Data error (cyclic redundancy check)
        at java.io.RandomAccessFile.readBytes(Native Method)
        at java.io.RandomAccessFile.read(RandomAccessFile.java:315)
        at P.Lucene.Expert.store.FSDirectory$FSIndexInput

When could be the problem here?
Since it threw the application, the index stayed open. Is there a
possibility to close it properly? to save the data?

Many thanks,
Liat