Friend as suggested I have done the below steps
1.Unregister all objects from the datastore including VMs and Templates
2.Ensure that no 3rd party tools are accessing the datastore
3.Ensure that no vSphere features, such as Storage I/O Control or Storage DRS, are using the device
4.Detach the device from the ESX host; this will also initiate an unmount operation
Note: The Detach function must be performed on a per-host basis and does not propagate to other hosts in vCenter Server. If a LUN is presented to an initiator group or storage group on the SAN, the Detach function must be performed on every host in that initiator group before unmapping the LUN from the group on the SAN. Failing to follow this step results in an all-paths-down (APD) state for those hosts in the storage group on which Detach was not performed for the LUN being unmapped.
5.Physically unpresent the LUN from the ESX host using the appropriate array tools.
as soon as lun unpreset from SAN I have started recived these errors in Host event tab
Lost connectivity to storage device naa.60060160f5a23400e8c4cb3f3a1de411. Path vmhba1:C0:T0:L26 is down. Affected datastores:
Unknown.
error
10-09-2014 12:19:34
Lost connectivity to storage device naa.60060160f5a234001624ba283a1de411. Path vmhba2:C0:T1:L22 is down. Affected datastores:
Unknown.
error
10-09-2014 12:19:34
Lost connectivity to storage device naa.60060160f5a23400e617c32e3a1de411. Path vmhba1:C0:T0:L23 is down. Affected datastores:
Unknown.
error
10-09-2014 12:19:34
Alarm 'Cannot connect to storage' on
dodadbsrv02.dodagumgrd.com changed from
Gray to Gray
info
10-09-2014 12:19:46
6.Rescan the SAN
7. esxcli storage core device detached list
esxcli storage core device detached remove -d naa.60060160f5a23400e8c4cb3f3a1de411
My question is y I have got these many error message in event tab , just want to confirm is there any step I have missed above or it's a genuine error message which is safe to ignore.
regards
Mr VMware