vsphere-esxi-vcenter-server-55-storage-guide

Chapter 16 Working with DatastoresChecking Metadata Consistency with VOMAUse VMware Ondisk Metadata Analyser (VOMA) when you experience problems with your VMFSdatastore and need to check metadata consistency of VMFS or logical volume backing the VMFS volume.ProblemThe following examples show circumstances in which you might need to perform a metadata check:• You experience SAN outages.• After you rebuild RAID or perform a disk replacement.• You see metadata errors in the vmkernel.log file.• You are unable to access files on the VMFS datastore that are not in use by any other host.SolutionTo check metadata consistency, run VOMA from the CLI of an ESXi host version 5.1 or later. VOMA cancheck both the logical volume and the VMFS for metadata inconsistencies. You can use VOMA on VMFS3and VMFS5 datastores. VOMA runs in a read-only mode and serves only to identify problems. VOMA doesnot fix errors that it detects. Consult VMware Support to resolve errors reported by VOMA.Follow these guidelines when you use the VOMA tool:• Make sure that the VMFS datastore you analyze does not span multiple extents. You can run VOMAonly against a single-extent datastore.• Power off any virtual machines that are running or migrate them to a different datastore.Follow these steps when you use the VOMA tool to check VMFS metadata consistency.1 Obtain the name and partition number of the device that backs the VMFS datastore that you need tocheck.#esxcli storage vmfs extent listThe Device Name and Partition columns in the output identify the device. For example:Volume Name XXXXXXXX Device Name1TB_VMFS5 XXXXXXXX naa.600508e000000000b367477b3be3d703 32 Run VOMA to check for VMFS errors.PartitionProvide the absolute path to the device partition that backs the VMFS datastore, and provide a partitionnumber with the device name. For example:# voma -m vmfs -f check -d /vmfs/devices/disks/naa.600508e000000000b367477b3be3d703:3The output lists possible errors. For example, the following output indicates that the heartbeat addressis invalid.XXXXXXXXXXXXXXXXXXXXXXXPhase 2: Checking VMFS heartbeat regionON-DISK ERROR: Invalid HB addressPhase 3: Checking all file descriptors.Phase 4: Checking pathname and connectivity.Phase 5: Checking resource reference counts.Total Errors Found: 1The VOMA tool uses the following options.VMware, Inc. 151