CA-413598/XSI-1954: Only block pool join for clustering on non-management VLAN

[gangj]

It is because the known issue is only with non-management VLAN:

https://docs.xenserver.com/en-us/xenserver/8/storage/format#thin-provisioned-shared-gfs2-block-storage

We recommend not to use a GFS2 SR with a VLAN due to a known issue where you cannot add or remove hosts on a clustered pool if the cluster network is on a non-management VLAN.

[MarkSymsCtx]

What stops fixing the general case here so that VLANs can be used? This would seem to be a generally beneficial improvement for customers?

[edwintorok]

What stops fixing the general case here so that VLANs can be used? This would seem to be a generally beneficial improvement for customers?

I think XAPI doesn't copy VLAN settings when joining a pool for anything except the management network.
That might be fixable, although in the end it won't gain you much: if the 2 VLANs end up sharing the same physical network then you have no benefit from separating the 2 networks: if one of the VLANs floods the interface, the other one might experience delays anyway, I don't think we do anything clever wrt to QoS between VLANs.

And if the VLANs would be on separate NICs, then you could just make the clustering network a non-VLAN network: the only hosts needing access to that are the clustering hosts, and those also have access to the non-vlan port already.

The management interface is different because that one needs to be accessed by external hosts (XC), which may only be able to reach it on the VLAN.

[lindig]

would use "… is enabled on a non-management VLAN network"