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Posted to users@cloudstack.apache.org by Jon Marshall <jm...@hotmail.co.uk> on 2018/06/20 07:25:27 UTC
Storage traffic clarification.
I am probably missing something obvious but according to this article (https://www.shapeblue.com/understanding-cloudstacks-physical-networking-architecture/) by default primary and secondary storage traffic travels across the management network.
As an example assume basic networking with 2 NICS, one for management with an IP subnet, the other NIC for guest traffic using a different subnet. A physical host should only have one default gateway and this would have to be from the guest VM subnet.
I setup two tests -
1) the NFS server had an IP address from the management subnet
2) the NFS server was on a completely different IP subnet ie. not the management or the guest IP subnets.
Both worked but in test 2 I can't see how the storage traffic could be using the management NIC because there is no default gateway on the compute nodes for the management subnet and the NFS server is on a remote network.
So is storage traffic in test 2 actually running across the guest NIC ?
And as the recommendation is to have separate storage from guest traffic does this mean the NFS server has to be in the management subnet ?
Thanks
Re: Storage traffic clarification.
Posted by Jon Marshall <jm...@hotmail.co.uk>.
Ilya
Thanks for the response.
So if I use cloudbr0 for management then define that on the storage icon as well when setting up a zone.
Is there something else I need to do as well though because when I set it up I have cloudbr0 for management and cloudbr1 for guest and in the network configuration files I only define a default gateway in the cloudbr1 file.
This is what caught me out originally ie. I defined a default gateway in both cloudbrx files and the SSVM chose the management vlan as it's default gateway so the guest traffic did not work. If i only set the default gateway in the guest subnet everything works but then the SSVM will have a default gateway in the guest IP subnet and as it does not have an interface in the NFS subnet it has to use that default gateway to get to the NFS server.
Perhaps I am not understanding how cloudstack is doing the routing internally ?
Jon
________________________________
From: ilya musayev <il...@gmail.com>
Sent: 20 June 2018 21:20
To: users@cloudstack.apache.org
Subject: Re: Storage traffic clarification.
Jon
with Basic Network - it implies you have all in one network for everything.
If you have a storage network that is L3 routable and you don’t want to use
guest network - then when you create a zone - use storage label and define
what bridge will be used to get there.
If it’s not guest bridge you wan to use - then use the management Bridge.
Regards
Ilya
On Wed, Jun 20, 2018 at 12:25 AM Jon Marshall <jm...@hotmail.co.uk> wrote:
> I am probably missing something obvious but according to this article (
> https://www.shapeblue.com/understanding-cloudstacks-physical-networking-architecture/)
[https://www.shapeblue.com/wp-content/uploads/2013/01/PhysicalNetworkingBlog_basNetWiz-300x239.png]<https://www.shapeblue.com/understanding-cloudstacks-physical-networking-architecture/>
Understanding CloudStack’s Physical Networking ...<https://www.shapeblue.com/understanding-cloudstacks-physical-networking-architecture/>
www.shapeblue.com
Understanding and configuring the physical connections of a host in a CloudStack deployment can at first be very confusing. While Software Defined Networking (SDN) is set to greatly simplify some aspects, its integration within CloudStack is not fully mature yet and it won’t be the right solution for everyone.
> by default primary and secondary storage traffic travels across the
> management network.
>
> As an example assume basic networking with 2 NICS, one for management with
> an IP subnet, the other NIC for guest traffic using a different subnet. A
> physical host should only have one default gateway and this would have to
> be from the guest VM subnet.
>
> I setup two tests -
>
> 1) the NFS server had an IP address from the management subnet
>
> 2) the NFS server was on a completely different IP subnet ie. not the
> management or the guest IP subnets.
>
> Both worked but in test 2 I can't see how the storage traffic could be
> using the management NIC because there is no default gateway on the compute
> nodes for the management subnet and the NFS server is on a remote network.
>
> So is storage traffic in test 2 actually running across the guest NIC ?
>
> And as the recommendation is to have separate storage from guest traffic
> does this mean the NFS server has to be in the management subnet ?
>
> Thanks
>
Re: Storage traffic clarification.
Posted by ilya musayev <il...@gmail.com>.
Jon
with Basic Network - it implies you have all in one network for everything.
If you have a storage network that is L3 routable and you don’t want to use
guest network - then when you create a zone - use storage label and define
what bridge will be used to get there.
If it’s not guest bridge you wan to use - then use the management Bridge.
Regards
Ilya
On Wed, Jun 20, 2018 at 12:25 AM Jon Marshall <jm...@hotmail.co.uk> wrote:
> I am probably missing something obvious but according to this article (
> https://www.shapeblue.com/understanding-cloudstacks-physical-networking-architecture/)
> by default primary and secondary storage traffic travels across the
> management network.
>
> As an example assume basic networking with 2 NICS, one for management with
> an IP subnet, the other NIC for guest traffic using a different subnet. A
> physical host should only have one default gateway and this would have to
> be from the guest VM subnet.
>
> I setup two tests -
>
> 1) the NFS server had an IP address from the management subnet
>
> 2) the NFS server was on a completely different IP subnet ie. not the
> management or the guest IP subnets.
>
> Both worked but in test 2 I can't see how the storage traffic could be
> using the management NIC because there is no default gateway on the compute
> nodes for the management subnet and the NFS server is on a remote network.
>
> So is storage traffic in test 2 actually running across the guest NIC ?
>
> And as the recommendation is to have separate storage from guest traffic
> does this mean the NFS server has to be in the management subnet ?
>
> Thanks
>