What do you do when you have problems accessing some files on a VMFS datastore or you cannot delete files on datastore? Well, all such problems related to VMFS datastore can now be detected and also can be fixed sometimes. VMware has introduced a new utility called vSphere On-Disk Metadata Analyzer(VOMA) in version 5.1 which can check the VMFS partition for any corrupted metadata, however, from version 6, a new option to fix the errors has also been introduced. This utility can be compared to CHKDSK utility in windows.
In this post, let’s learn how to use that and fix things in case of issues. A VMware support request is recommended when an inconsistency is detected.
Before performing the Metadata check, make sure that
- There are no VMs on the datastore you wish to analyze
- For VMFS-5 datastores, the datastore is unmounted on all ESXi hosts.
- For VMFS-3 which has ESXi4 and 3.x hosts, the LUNs must be masked using claimrules. Refer my previous post on How To
- The volume affected is not a multi extent volume. VOMA cannot analyze a datastore built from multiple extents.
Below are the datastores that my ESXi host can see and say i want to analyze LUN1-P, note the device id and partition.
The command to analyze the device is as below
voma -m vmfs -d /vmfs/devices/disks/eui.58692b53cd02d30b:1
If the volume is being accessed by any hosts, VOMA gives an error message displaying the MAC addresses of the hosts as below.
So let’s unmont the datastore from the host. Once done, repeat the above command.
VOMA checks the metadata in different phases and reports the errors if any.
ESXi 6.0 hosts include VOMA with check and fix option and it is always recommended to have a latest backup of VMs and open a support case.
Hope this was informative. Thanks!