Running Release 5.0.1_GA_1902.UBUNTU6 (Network Edition)

At some point backups started reporting FAIL. I'm seeing a bunch of entries like this in the mailbox.log file:

Code:
2008-03-26 01:01:10,369 INFO  [btpool0-3248] [name=zimbra;ip=127.0.0.1;] SoapEngine - handler exception
com.zimbra.common.service.ServiceException: system failure: unable to read metadata for account e08bc6bd-d835-4262-8a56-7365c3313789 backup full-20080308.060007.994
Code:service.FAILURE
        at com.zimbra.common.service.ServiceException.FAILURE(ServiceException.java:183)
        at com.zimbra.cs.service.backup.Backup.handleNetworkRequest(Backup.java:150)
        at com.zimbra.cs.service.NetworkDocumentHandler.handle(Unknown Source)
        at com.zimbra.soap.SoapEngine.dispatchRequest(SoapEngine.java:342)
        at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.java:208)
        at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.java:113)
        at com.zimbra.soap.SoapServlet.doPost(SoapServlet.java:272)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
        at com.zimbra.cs.servlet.ZimbraServlet.service(ZimbraServlet.java:174)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
        at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487)
        at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1093)
        at org.mortbay.servlet.UserAgentFilter.doFilter(UserAgentFilter.java:81)
        at org.mortbay.servlet.GzipFilter.doFilter(GzipFilter.java:148)
        at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1084)
        at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:360)
        at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
        at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)
        at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:716)
        at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:406)
        at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:211)
        at org.mortbay.jetty.handler.HandlerCollection.handle(HandlerCollection.java:114)
        at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:139)
        at org.mortbay.jetty.handler.RewriteHandler.handle(RewriteHandler.java:176)
        at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:139)
        at org.mortbay.jetty.Server.handle(Server.java:313)
        at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:506)
        at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:844)
        at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:644)
        at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:211)
        at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:381)
        at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:396)
        at org.mortbay.thread.BoundedThreadPool$PoolThread.run(BoundedThreadPool.java:442)
Caused by: java.io.IOException: unable to read metadata for account e08bc6bd-d835-4262-8a56-7365c3313789 backup full-20080308.060007.994
        at com.zimbra.cs.backup.util.Utils.IOException(Utils.java:203)
        at com.zimbra.cs.backup.FileBackupTarget$RestoreAcctSession.<init>(FileBackupTarget.java:1571)
        at com.zimbra.cs.backup.FileBackupTarget.getAccountSession(FileBackupTarget.java:321)
        at com.zimbra.cs.backup.FileBackupTarget.getAccountSession(FileBackupTarget.java:303)
        at com.zimbra.cs.backup.BackupManager.backupIncremental(BackupManager.java:292)
        at com.zimbra.cs.service.backup.Backup.handleNetworkRequest(Backup.java:143)
        ... 31 more
Caused by: com.zimbra.common.service.ServiceException: system failure: Unable to parse XML file /opt/zimbra/backup/sessions/full-20080308.060007.994/a
ccounts/e08/bc6/e08bc6bd-d835-4262-8a56-7365c3313789/meta.xml
Code:service.FAILURE
        at com.zimbra.common.service.ServiceException.FAILURE(ServiceException.java:183)
        at com.zimbra.cs.backup.XmlMeta.readAccountBackup(XmlMeta.java:381)
        at com.zimbra.cs.backup.FileBackupTarget$RestoreAcctSession.<init>(FileBackupTarget.java:1568)
        ... 35 more
Caused by: java.io.IOException: Input/output error
2008-03-26 01:01:10,369 INFO  [btpool0-3248] [name=zimbra;ip=127.0.0.1;] SoapEngine - handler exception
com.zimbra.common.service.ServiceException: system failure: unable to read metadata for account e08bc6bd-d835-4262-8a56-7365c3313789 backup full-20080
308.060007.994
Code:service.FAILURE
        at com.zimbra.common.service.ServiceException.FAILURE(ServiceException.java:183)
        at com.zimbra.cs.service.backup.Backup.handleNetworkRequest(Backup.java:150)
        at com.zimbra.cs.service.NetworkDocumentHandler.handle(Unknown Source)
        at com.zimbra.soap.SoapEngine.dispatchRequest(SoapEngine.java:342)
        at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.java:208)
        at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.java:113)
        at com.zimbra.soap.SoapServlet.doPost(SoapServlet.java:272)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
        at com.zimbra.cs.servlet.ZimbraServlet.service(ZimbraServlet.java:174)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
        at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487)
        at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1093)
        at org.mortbay.servlet.UserAgentFilter.doFilter(UserAgentFilter.java:81)
        at org.mortbay.servlet.GzipFilter.doFilter(GzipFilter.java:148)
        at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1084)
        at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:360)
        at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
        at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)
        at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:716)
        at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:406)
        at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:211)
        at org.mortbay.jetty.handler.HandlerCollection.handle(HandlerCollection.java:114)
        at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:139)
        at org.mortbay.jetty.handler.RewriteHandler.handle(RewriteHandler.java:176)
        at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:139)
        at org.mortbay.jetty.Server.handle(Server.java:313)
        at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:506)
        at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:844)
        at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:644)
        at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:211)
        at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:381)
        at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:396)
        at org.mortbay.thread.BoundedThreadPool$PoolThread.run(BoundedThreadPool.java:442)
Caused by: java.io.IOException: unable to read metadata for account e08bc6bd-d835-4262-8a56-7365c3313789 backup full-20080308.060007.994
        at com.zimbra.cs.backup.util.Utils.IOException(Utils.java:203)
        at com.zimbra.cs.backup.FileBackupTarget$RestoreAcctSession.<init>(FileBackupTarget.java:1571)
        at com.zimbra.cs.backup.FileBackupTarget.getAccountSession(FileBackupTarget.java:321)
        at com.zimbra.cs.backup.FileBackupTarget.getAccountSession(FileBackupTarget.java:303)
        at com.zimbra.cs.backup.BackupManager.backupIncremental(BackupManager.java:292)
        at com.zimbra.cs.service.backup.Backup.handleNetworkRequest(Backup.java:143)
        ... 31 more
Caused by: com.zimbra.common.service.ServiceException: system failure: Unable to parse XML file /opt/zimbra/backup/sessions/full-20080308.060007.994/a
ccounts/e08/bc6/e08bc6bd-d835-4262-8a56-7365c3313789/meta.xml
Code:service.FAILURE
        at com.zimbra.common.service.ServiceException.FAILURE(ServiceException.java:183)
        at com.zimbra.cs.backup.XmlMeta.readAccountBackup(XmlMeta.java:381)
        at com.zimbra.cs.backup.FileBackupTarget$RestoreAcctSession.<init>(FileBackupTarget.java:1568)
        ... 35 more
Caused by: java.io.IOException: Input/output error
        at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:139)
        at org.mortbay.jetty.handler.RewriteHandler.handle(RewriteHandler.java:176)
        at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:139)
        at org.mortbay.jetty.Server.handle(Server.java:313)
        at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:506)
        at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:844)
        at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:644)
        at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:211)
        at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:381)
        at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:396)
        at org.mortbay.thread.BoundedThreadPool$PoolThread.run(BoundedThreadPool.java:442)
2008-03-26 01:02:14,245 INFO  [IndexWritersSweeperThread] [] index - open index writers sweep: before=2, closed=0, after=2 (0ms)
2008-03-26 01:02:40,152 INFO  [btpool0-3197] [name=zimbra;ip=127.0.0.1;] backup - Backup request finished
I have checked the disk file system, there are no errors. Any ideas?