solr failing on staartup

[Harish Rawat]

Hi Guys

The solr server which was running fine for last few months, is now failing
during startup wuth following error

Sep 19, 2012 12:53:25 PM org.apache.solr.common.SolrException log
SEVERE: java.lang.RuntimeException: java.io.FileNotFoundException:
/var/lib/solr/default/index/.cfs (No such file or directory)
        at org.apache.solr.core.SolrCore.getSearcher(SolrCore.java:1103)
        at org.apache.solr.core.SolrCore.<init>(SolrCore.java:587)
        at org.apache.solr.core.CoreContainer.create(CoreContainer.java:463)
        at org.apache.solr.core.CoreContainer.load(CoreContainer.java:316)
        at
org.apache.solr.core.CoreContainer$Initializer.initialize(CoreContainer.java:133)
        at
org.apache.solr.servlet.SolrDispatchFilter.init(SolrDispatchFilter.java:94)
        at
org.mortbay.jetty.servlet.FilterHolder.doStart(FilterHolder.java:97)
        at
org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
        at
org.mortbay.jetty.servlet.ServletHandler.initialize(ServletHandler.java:662)
        at org.mortbay.jetty.servlet.Context.startContext(Context.java:140)
        at
org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1250)
        at
org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:517)
        at
org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:467)
        at
org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
        at
org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:152)

Does any one know what could be possible reasons for failure?

Regards
Harish