[ovirt-users] Re: iSCSI Multipath/multiple gateways
Am 03.09.19 um 15:06 schrieb dan.poltawski(a)tnp.net.uk:
My iSCSI target (ceph-based) has multiple gateways, I’d like to
ensure my hosted storage is aware of these such that each gateway can be rebooted for
maintance without impacting service. What is the appropriate way to configure this so that
each host knows of the multipath configuration? I do not have multiple network paths, just
multiple gateways on the same network, so I think the multipath UI tool isn’t the way to
do this.
Any help/docs pointers appreciated.
Regards,
Dan
Hi,
I'm also planning to use a 2 node Ceph iSCSI gateway with oVirt. Right
now I only connected it to my DEV oVirt environment, but everything
works as expected (finally...), so I might be moving it to PROD soon.
My circumstances and findings:
- I'm only using it for customer VM storage, I don't have a hosted engine
- my 2 Ceph iSCSI gateway nodes are also on the same network (network
connection redundancy is through LACP bonds for them)
- oVirt storage domain setup automatically finds both gateways when you
"discover" one of them, you must log into both
- multipath configuration on hypervisor hosts is then automatically set
up without further intervention. be sure to add the multipath.conf
snippets from
https://docs.ceph.com/docs/master/rbd/iscsi-initiator-linux/ to your
hypervisor hosts, so multipathd works correctly (I originally forgot to
do this...)
- what is called "ISCSI Multipathing" in oVirt on DC level only creates
iscsiadm "ifaces" (see man iscsiadm), which are not strictly necessary
IMHO, but are of use in special networking situations. the logical
networks you use there must not be "required" in Cluster "Logical
networks" setup
I hope this helps
Matthias