Last week I was trying to determine the root cause of a storage connection issue that I had and came across the following message in the fdm.log. The message repeated every second until the host was rebooted (this had resolved the storage connection problem):
2012-11-05T04:46:01.179Z [FFA7DB90 verbose 'Cluster' opID=SWI-cee8d54c] [HBDatastore::Heartbeat] 1 ios in progress for /vmfs/volumes/4daedc7c-6b68ec0d-916c-00219b8fbdcc
There were two errors in the fdm.log that preceeded the above error:
2012-11-05T01:02:52.502Z [FFBC2B90 warning 'Cluster' opID=SWI-79958859] [VmfsUtils::VerifyFileLock] VmkuserVMFS_VerifyLock returned error Unknown error status: 0xbad0001
2012-11-05T01:02:52.503Z [FFBC2B90 error 'Cluster' opID=SWI-79958859] [HBDatastore::DoHeartbeat] Lock verify for file /vmfs/volumes/4daedca2-10ab4da4-2e3a-00219b8fbdcc/.vSphere-HA/FDM-F9B29C80-2A7D-4E30-BCC7-BE9209A39F59-7-d638721-/host-43-hb failed: Invalid argument
My question is, what does "1 ios in progress for <volume name>" represent? I imagine since I was having storage issues that it is related to some datastore heartbeating of some sort, but I can't find any reference to what it means.