Identifying Fibre Channel, iSCSI, and NFS storage issues on ESX/ESXi hosts

No targets from an array can be seen by:
- All of the ESX/ESXi hosts
- All of the ESX/ESXi hosts on a specific connection or LUN
- One ESX/ESXi host
Targets on the storage array are visible, but one or more LUNs are not
LUN not visible
LUN cannot connect
Connectivity issues to the storage array
ESX/ESXi host initiators are not logging into the array
The share cannot be mounted by the ESX/ESXi host
The share is mounted, but nothing can be written to it
You see one or more of the following errors:
- Unknown inaccessible
- SCSI: 4506: Cannot find a path to device vmhbax:x:x in a good state
- WARNING: LVM: 4844: vmhbaH:T:L:P detected as a snapshot device. Disallowing access to the LUN since resignaturing is turned off.
- Date esx vmkernel: Time cpu3: : 5637: status SCSI LUN is in snapshot state, rstatus 0xc0de00 for vmhbax:x:x. residual R 999, CR 8-, ER3
- Date esx vmkernel: Time cpu3: world ID SCSI 6624: Device vmhbax:x:x. is a deactivated snapshot

Purpose

This article helps you identify problems related with the storage subsystem of ESX/ESXi.

Resolution

Troubleshooting ESX host storage issues begins with identifying how far reaching (the scope) the problem is. In many cases, a detected problem may be misidentified until the scope has been ascertained.

To identify the scope of the problem:

Verify that the storage device cannot be seen by any or a subset of the ESX cluster. If so, select the appropriate storage technology:
- For Fibre channel, see Troubleshooting fibre channel storage connectivity (1003680).
- For iSCSI connected by hardware initiator, see Troubleshooting iSCSI array connectivity (1003681).
- For NFS, see Troubleshooting connectivity issues to an NFS data store (1003967).
Verify that no more than a single ESX host cannot see the shared storage. If so, select the appropriate storage technology:
- For iSCSI connected by hardware initiator, see Troubleshooting ESX and ESXi connectivity to iSCSI arrays using hardware initiators (1003951).
- For iSCSI connected by software initiator, see Troubleshooting ESX and ESXi connectivity to iSCSI arrays using software initiators (1003952).
- For NFS, see Troubleshooting connectivity issues to an NFS datastore (1003967).
Verify that the LUN is presented and available. For more information, see Troubleshooting LUN connectivity issues (1003955).
Verify that the ESX host cannot see the datastore:
- For Fibre channel or iSCSI, see Troubleshooting VMFS-3 datastore issues (1003964).
- For NFS, see Troubleshooting connectivity issues to an NFS datastore (1003967).