Resolving a problem with PFC settings

This procedure provides a solution for Internet Small Computer Systems Interface (iSCSI) with PFC settings.

About this task

The portsets are associated with the different functions like host attach, storage, and replication. For each portset lossless attribute of lsportset command indicates that all the IP addresses for the portset are lossless. The ON value in the lossless attribute of lsportsetcommand indicates that PFC is enabled for that portset. Even if a single IP address is not configured as lossless, the portset is not a lossless portset. Use lsip to view lossless parameter per IP address.

Procedure

Troubleshoot problems with PFC settings.
In the lsip command output, the lossless parameter indicates whether PFC is enabled for the IP address or not. The ON value indicates PFC is enabled on the IP address. However, several off states indicate the problem that might prevent PFC to be enabled on the IP address:
  1. If the off-not_supported is displayed in the lossless, it indicates that IP address is associated with portset of type replication. Verify the followings:
    • Check the portset for the IP address by using lsip command.
    • Change the portset to host attach if the IP address needs to be PFC enabled.
  2. If the off-vlan_not_configured is displayed in the lossless, it indicates that IP address is associated with non-VLAN interface. Verify the followings:
    • Check the VLAN information for IP using lsip command.
    • Add the IP address with VLAN if same needs to be PFC enabled.
  3. If the off-eth_port_not_enabled_for_pfc is displayed in the lossless, it indicates that IP address is associated with the port where PFC is not configured correctly.
If lsip command output displays eth_port_not_enabled_for_pfc as lossless attribute value, then verify the followings:
  1. Whether DCBx is enabled for that port:
    • -dcbx_state attribute of lsportethernet command displays the Data Center Bridging Capability Exchange protocol (DCBx) state of the port. You must enable it for PFC to work. DCBx state does not support for networks with the speed lesser than 10G.
  2. For the host attach type portsets and the associated IP addresses, check pfc_enabled_host_attach field of lsportethernet command. The field displays whether a PFC tag for host attach is enabled on to the connected switch port or not. It displays the followings:
    • no-link_inactive if the link is inactive.
    • no-priority_tag_not_enabled_on_switch if the host attach cos value is set by using chsystemethernet command is not enabled on switch.
    • Yes if PFC settings are done correctly on that port.
  3. For the storage type portsets and the associated IP addresses, check pfc_enabled_storage field of lsportethernet command that displays whether a PFC tag for storage is enabled on the connected switch port or not. The field displays the followings:
    • no-link_inactive if the link is inactive.
    • no-priority_tag_not_enabled_on_switch if the storage cos value that is set using chsystemethernet command is not enabled on switch.
    • Yes if PFC settings are done correctly on that port.
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