Perform troubleshooting tasks if iSCSI storage devices do not display correctly in the vSphere Web Client.

Table 1. Troubleshooting iSCSI LUN Display
Troubleshooting Task Description
Check cable connectivity. If you do not see a port, the problem could be cable connectivity or routing. Check the cables first. Ensure that cables are connected to the ports and a link light indicates that the connection is good. If each end of the cable does not show a good link light, replace the cable.
Check routing settings. Controls connectivity between different subnets on your Ethernet configuration. If your ESXi system and iSCSI storage are not on the same subnet, ensure that appropriate routing exists between the subnets. Also, ensure that the subnet mask and gateway address are set correctly on the iSCSI storage and the iSCSI initiator in the ESXi host.
Check access control configuration. If the expected LUNs do not appear after rescan, access control might not be configured correctly on the storage system side:
  • If CHAP is configured, ensure that it is enabled on the ESXi host and matches the storage system setup.
  • If IP-based filtering is used, ensure that the iSCSI HBA or the VMkernel port group IP address is allowed.
  • If you are using initiator name-based filtering, ensure that the name is a qualified iSCSI name and matches the storage system setup.
  • For booting from a SAN, ensure that each host sees only required LUNs. Do not allow any host to see any boot LUN other than its own. Use storage system software to make sure that the host can see only the LUNs that it is supposed to see.
  • Ensure that theDisk.MaxLUN setting allows you to view the LUN you expect to see. For information, see the vSphere Storage documentation.
Check storage processor setup. If a storage system has more than one storage processor, make sure that the SAN switch has a connection to the SP that owns the LUNs you want to access. On some storage systems, only one SP is active and the other SP is passive until a failure occurs. If you are connected to the wrong SP (the one with the passive path) you might not see the expected LUNs, or you might see the LUNs but get errors when trying to access them.
For software and dependent hardware iSCSI, check network configuration. The software iSCSI and dependent hardware adapters in ESXi require that VMkernel network port have access to the iSCSI storage. The adapters use the VMkernel for data transfer between the ESXi system and the iSCSI storage.
Rescan your iSCSI initiator. Perform a rescan each time you complete the following tasks:
  • Create new LUNs on a SAN.
  • Change the LUN masking.
  • Reconnect a cable.
  • Make a change to a host in a cluster.
  • Change CHAP settings or add new discovery addresses.
For information, see the vSphere Storage documentation.