system error when space created in version 5.1.5

[pradheep.halan]

I was trying to create space in confluence version 5.1.5. But it is throwing system error. Please do the needful to resolve this issue.

Error:

com.atlassian.bonnie.LuceneException: com.atlassian.bonnie.LuceneException: Couldn't open writer on directory: org.apache.lucene.store.SimpleFSDirectory@/app/confl/ConfluenceHome/index lockFactory=org.apache.lucene.store.SimpleFSLockFactory@1f918a5b
    at com.atlassian.bonnie.LuceneConnection.withBatchUpdate(LuceneConnection.java:409)

caused by: com.atlassian.bonnie.LuceneException: Couldn't open writer on directory: org.apache.lucene.store.SimpleFSDirectory@/app/confl/ConfluenceHome/index lockFactory=org.apache.lucene.store.SimpleFSLockFactory@1f918a5b
    at com.atlassian.bonnie.LuceneConnection.withWriter(LuceneConnection.java:346)

caused by: org.apache.lucene.store.LockObtainFailedException: Lock obtain timed out: SimpleFSLock@/app/confl/ConfluenceHome/index/write.lock
    at org.apache.lucene.store.Lock.obtain(Lock.java:85)

[Nic Brough -Adaptavist-]

Check the permissions and ownership of the fhe directory named in the error message, and the files in the directory.

Also, check that there is enough disk space and inodes free to allow Confluence to create more files and add to existing ones.