Assumptions that need to be confirmed:
- you have done a rescan on all hosts before attempting to increase datastore size
- 172.18.100.48 is not the only host in vCenter inventory
- volDatastoreE is currently accessible by multiple hosts
- NetApp LUNs, visible by host 48 (0,1,2,13,17) are not presented to other hosts, that are currently accessing volDatastoreE
If all of the above are true then this is by design. vCenter has storage filters that do not allow you to add extent to existing datastore if that extent is not accessible by all hosts that are currently accessing the datastore you are trying to increase.
To resolve this:
- ask your storage admin to present the NetApp LUN(s) you want to add as an extent to all hosts that currently can see the datastore you want to increase, make sure the LUNs are presented with same LUN numbers (i.e. if particular LUN is presented as LUN 17 to one host, it should be presented as LUN 17 to all remaining hosts)
- do a rescan on all hosts
- try increasing datastore from vCenter again
hope this helps
p.s. if you want to get some more info on storage filtering, check the storage guide: http://pubs.vmware.com/vsphere-51/topic/com.vmware.vsphere.storage.doc/GUID-352D574A-CB43-4275-97AB-822EE294BC93.html
don't turn them off unless you are absolutely sure you know what you're doing. They are there for a reason!
WBR
Imants