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Table Of Contents
Resolving iSCSI Storage Display Problems
Perform troubleshooting tasks if iSCSI storage devices do not display correctly in the vSphere Web Client.
Table 72. 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:
n
If CHAP is configured, ensure that it is enabled on the ESXi host and matches the
storage system setup.
n
If IP-based filtering is used, ensure that the iSCSI HBA or the VMkernel port group
IP address is allowed.
n
If you are using initiator name-based filtering, ensure that the name is a qualified
iSCSI name and matches the storage system setup.
n
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.
n
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:
n
Create new LUNs on a SAN.
n
Change the LUN masking.
n
Reconnect a cable.
n
Make a change to a host in a cluster.
n
Change CHAP settings or add new discovery addresses.
For information, see the vSphere Storage documentation.
Resolving SAN Performance Problems
A number of factors can negatively affect storage performance in the ESXi SAN environment. Among these
factors are excessive SCSI reservations, path thrashing, and inadequate LUN queue depth.
To monitor storage performance in real time, use the resxtop and esxtop command-line utilities. For more
information, see the vSphere Monitoring and Performance documentation.
Chapter 7 Troubleshooting Storage
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