Do primary and secondary storage must be served by different servers ?

[Yiping Zhang <yz...@marketo.com>]

I need some clarifications regarding primary and secondary storage devices.

>From following document, http://cloudstack-installation.readthedocs.org/en/latest/hypervisor/xenserver.html

In section "Separate Storage Network for XenServer (Optional)”, it states, I quote:

For the separate storage network to work correctly, it must be the only interface that can ping the primary storage device’s IP address. For example, if eth0 is the management network NIC, ping -I eth0 <primary storage device IP> must fail. In all deployments, secondary storage devices must be pingable from the management network NIC or bond. If a secondary storage device has been placed on the storage network, it must also be pingable via the storage network NIC or bond on the hosts as well.

In my case, since both primary and secondary storage are from the same NetApp filer, just two different volumes,  so those two sentences highlighted red above can’t possibly be true at the same time !  As it is now,  I can ping my filer from storage bond, as well as from management bond on xen hypervisor.

Does this mean my primary and secondary storage volumes can not be served by the same filer ?

Thanks for your help in advance.

Yiping

Re: Do primary and secondary storage must be served by different servers ?

[Tim Mackey <tm...@gmail.com>]

What that statement means is if you explicitly define a dedicated storage
network (aka for primary storage), then that storage network can't be
pingable from the management network.  This is no different than if you
define a storage management network in XenServer directly.

Where things get a bit more complicated is with Secondary Storage which
uses a VM as a proxy to the storage.  That VM is known as SSVM, and some
details on how to debug it can be found here:
https://cwiki.apache.org/confluence/display/CLOUDSTACK/SSVM,+templates,+Secondary+storage+troubleshooting

The net of this is that primary and secondary can definitely be on the same
file.  Things can get more complicated if you need different storage for
primary and secondary, or multipath, and for XenServer the CloudStack
storage option you might also want to look into is called PreSetup.

-tim

On Fri, Oct 3, 2014 at 2:44 PM, Yiping Zhang <yz...@marketo.com> wrote:

> I need some clarifications regarding primary and secondary storage devices.
>
> From following document,
> http://cloudstack-installation.readthedocs.org/en/latest/hypervisor/xenserver.html
>
> In section "Separate Storage Network for XenServer (Optional)”, it states,
> I quote:
>
> For the separate storage network to work correctly, it must be the only
> interface that can ping the primary storage device’s IP address. For
> example, if eth0 is the management network NIC, ping -I eth0 <primary
> storage device IP> must fail. In all deployments, secondary storage devices
> must be pingable from the management network NIC or bond. If a secondary
> storage device has been placed on the storage network, it must also be
> pingable via the storage network NIC or bond on the hosts as well.
>
> In my case, since both primary and secondary storage are from the same
> NetApp filer, just two different volumes,  so those two sentences
> highlighted red above can’t possibly be true at the same time !  As it is
> now,  I can ping my filer from storage bond, as well as from management
> bond on xen hypervisor.
>
> Does this mean my primary and secondary storage volumes can not be served
> by the same filer ?
>
> Thanks for your help in advance.
>
> Yiping
>