MPIO by concept is when you have two dedicated paths for iSCSI. So you don’t put iSCSI inside LACP, because it won’t do the MPIO magic. Since it’s the same path with a single IP.
The right approach is two subjects, completely segregated without routing. You can use the same switch, it will not be redundant on the switch part, but it will be on the connections and you have two paths to follow load balancing between them. But to be honest I never get how oVirt handles MPIO. The iSCSI Multipath button on the interface request that all points, on different paths, to be reached, which doesn’t make sense for my understanding. In the past I’ve opened a ticket about this but I simply gave up. Ended using XenServer instead for this case specifically, which I was trying to avoid. Sent from my iPhone > On 17 Jan 2019, at 22:14, John Florian <[email protected]> wrote: > > I have an existing 4.2 setup with 2 hosts, both with a quad-gbit NIC and a > QNAP TS-569 Pro NAS with twin gbit NIC and five 7k2 drives. At present, the > I have 5 VLANs, each with their own subnet as: > > my "main" net (VLAN 1, 172.16.7.0/24) > ovirtmgmt (VLAN 100, 192.168.100.0/24) > four storage nets (VLANs 101-104, 192.168.101.0/24 - 192.168.104.0/24) > On the NAS, I enslaved both NICs into a 802.3ad LAG and then bound an IP > address for each of the four storage nets giving me: > > bond0.101@bond0: 192.168.101.101 > bond0.102@bond0: 192.168.102.102 > bond0.103@bond0: 192.168.103.103 > bond0.104@bond0: 192.168.104.104 > The hosts are similar, but with all four NICs enslaved into a 802.3ad LAG: > > Host 1: > > bond0.101@bond0: 192.168.101.203 > bond0.102@bond0: 192.168.102.203 > bond0.103@bond0: 192.168.103.203 > bond0.104@bond0: 192.168.104.203 > Host 2: > > bond0.101@bond0: 192.168.101.204 > bond0.102@bond0: 192.168.102.204 > bond0.103@bond0: 192.168.103.204 > bond0.104@bond0: 192.168.104.204 > I believe my performance could be better though. While running bonnie++ on a > VM, the NAS reports top disk throughput around 70MB/s and the network (both > NICs) topping out around 90MB/s. I suspect I'm being hurt by the load > balancing across the NICs. I've played with various load balancing options > for the LAGs (src-dst-ip and src-dst-mac) but with little difference in > effect. Watching the resource monitor on the NAS, I can see that one NIC > almost exclusive does transmits while the other is almost exclusively > receives. Here's the bonnie report (my apologies to those reading plain-text > here): > > Version 1.97 Sequential Output Sequential Input Random > Seeks > Sequential Create Random Create > > Size Per Char Block Rewrite Per Char Block Num Files > Create Read Delete Create Read Delete > > K/sec % CPU K/sec % CPU K/sec % CPU K/sec % CPU K/sec % CPU > /sec % CPU > /sec % CPU /sec % CPU /sec % CPU /sec % CPU /sec % CPU > /sec % CPU > unamed 4G 267 97 75284 21 22775 8 718 > 97 43559 7 189.5 8 16 6789 60 +++++ +++ > 24948 75 14792 86 +++++ +++ 18163 51 > Latency 69048us 754ms 898ms 61246us 311ms 1126ms Latency 33937us > 1132us 1299us 528us 22us 458us > > > I keep seeing MPIO mentioned for iSCSI deployments and now I'm trying to get > my head around how to best set that up or to even know if it would be > helpful. I only have one switch (a Catalyst 3750g) in this small setup so > fault tolerance at that level isn't a goal. > > So... what would the recommendation be? I've never done MPIO before but know > where it's at in the web UI at least. > > -- > John Florian > _______________________________________________ > Users mailing list -- [email protected] > To unsubscribe send an email to [email protected] > Privacy Statement: https://www.ovirt.org/site/privacy-policy/ > oVirt Code of Conduct: > https://www.ovirt.org/community/about/community-guidelines/ > List Archives: > https://lists.ovirt.org/archives/list/[email protected]/message/6PFUJFCL36VDEI6J6YUBGJNXTJHFQLYX/
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