openstack/os-brick
Code Issues Proposed changes

Update supported transports for iscsi connector

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In the case that a compute host with multiple NICs can be connectted to
iscsi storage network, we expect the storage traffic only be
transimitted via storage NIC. This need to define an custom iface and set the
iface.net_ifacename value to the storage interface name.

Unfortunately, the current iscsi connector does not support to use a
custom iface. The _validate_iface_transport will change it to default.
After add tcp to the supported_transports, it is possible to use a
custom iface.

Please get the details as below:
1. CMP001 has three NICs: NIC1 is for management network, NIC2 is
for tenant network, and NIC3 is for storage network. NIC3 can access
storage device via layer 2 network. And NIC1 can access storage device
too, but it can only access via layer 3 network. We hope all the storage
traffic only be transimitted via NIC3, because they are in the same
layer 2 network.
2. Get the NIC3 MAC:
   fa:16:3e:79:fd:63
3. Add new iscsi iface:
   # iscsiadm -m iface --op=new -I tcp.fa:16:3e:79:fd:63
   # iscsiadm -m iface -I tcp.fa:16:3e:79:fd:63 --op=update
              -n iface.hwaddress -v fa:16:3e:79:fd:63
4. Edit nova.conf, and change iscsi_iface value:
   iscsi_iface = tcp.fa:16:3e:79:fd:63
5. Restart nova compute service:
   # systemctl restart openstack-nova-compute

Without this change, _validate_iface_transport will change the
custom iface tcp.fa:16:3e:79:fd:63 to default due to it cannot find tcp
transport.

According to this change, we should have a corresponding change to the
nova docs, here is change to nova
https://review.openstack.org/#/c/524443/

Change-Id: I85a62cb6e7f8d8982e97e792d647d38ce5641060
Closes-Bug:#1722432
This commit is contained in:
Jack Lu 2017-10-10 15:04:57 +08:00
parent f6af1d21f0
commit cfe5b19fad
2 changed files with 9 additions and 2 deletions
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4
os_brick/initiator/connectors/iscsi.py
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@ -42,7 +42,7 @@ class ISCSIConnector(base.BaseLinuxConnector, base_iscsi.BaseISCSIConnector):
"""Connector class to attach/detach iSCSI volumes."""
supported_transports = ['be2iscsi', 'bnx2i', 'cxgb3i', 'default',
'cxgb4i', 'qla4xxx', 'ocs', 'iser']
'cxgb4i', 'qla4xxx', 'ocs', 'iser', 'tcp']
VALID_SESSIONS_PREFIX = ('tcp:', 'iser:')
def __init__(self, root_helper, driver=None,
@ -267,7 +267,7 @@ class ISCSIConnector(base.BaseLinuxConnector, base_iscsi.BaseISCSIConnector):
"""Check that given iscsi_iface uses only supported transports
Accepted transport names for provided iface param are
be2iscsi, bnx2i, cxgb3i, cxgb4i, default, qla4xxx, ocs or iser.
be2iscsi, bnx2i, cxgb3i, cxgb4i, default, qla4xxx, ocs, iser or tcp.
Note the difference between transport and iface;
unlike default(iscsi_tcp)/iser, this is not one and the same for
offloaded transports, where the default format is

7
releasenotes/notes/bug-1722432-2408dab55c903c5b.yaml Normal file
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@ -0,0 +1,7 @@
---
fixes:
- |
[`bug 1722432 <https://bugs.launchpad.net/os-brick/+bug/1722432>`_]
Changes the supported_transports to support tcp transport. With this
change, we can define an custom iface with tcp transport to limit the
storage traffic only be transimitted via storage NIC we specified.