topic Re: Samba in cluster with different TCP/IP subnets in Operating System - OpenVMS

Samba in cluster with different TCP/IP subnets

Michael Menge — Thu, 04 Nov 2010 13:43:26 GMT

We have a 5 node cluster at 3 different locations (with different subnets), all nodes with VMS 8.3 and samba V1.1-1 on local system disks. For cluster traffic there is a VPN with no IP defined on the NIC's. The nodes at each location share a locaton specific cluster ip address (registered in DNS).

Configuration ist as follows:
Node-Name K4 K7 K5 K6 K3
Typ IA64 IA64 IA64 IA64 AXP
Location LE LE LN LN LV
IP e.x4 e.x7 n.x5 n.x6 v.x3
Cluster-IP e.xc e.xc n.xc n.xc
Cluster-Name LE_C LE_C LN_C LN_C

smb.conf:
netbios name K4 K7 K5 K6 K3
netbios alias LE_C LE_C LN_C LN_C

Data is shared betweeen location LE and LN by HBVS; common SYSUAF and RIGHTSLIST database.
User connect to resource LE_C and in case of failure can manually switch to the nodes at location LN by using resource LN_C.
Now we want to create an additional cluster wide resource name which switch automatically between the two locations. We can install on or backup SAMBA$ROOT to an shadow set, but we cannot change the cluster ip addresses. Furthermore the cifs admin guide says that all nodes have to be in the same TCP/IP subnet (why? also necessary for cluster traffic going over VPN?).
So what options do we have? Can we simply define another common cluster alias for all 4 IA64-nodes? Do we have to use netbios alias? Which configuration parameters in smb.conf do we have to adjust?

Re: Samba in cluster with different TCP/IP subnets

Brad McCusker — Fri, 05 Nov 2010 11:44:45 GMT

Michael,

You did a great job describing your environment. Thank you.

Unfortunately, I am struggling to understand how you are currently using it, and what you are trying to do. Some thoughts and questions that might help me to understand your question:

1. Upgrade to CIFS 1.2. Its a much more stable product. And it might have some cluster improvements (I don't remember and I didn't look)

>smb.conf:
>netbios name K4 K7 K5 K6 K3
>netbios alias LE_C LE_C LN_C LN_C

I assume this means you have 5 different CIFs installations, one on each node?

>Now we want to create an additional
>cluster wide resource name which switch
>automatically between the two locations.

Under what circumstances do you want it to "switch automatically"? Are you talking about failover? Load Balancing?

>We can install on or backup SAMBA$ROOT
>to an shadow set, but we cannot change the >cluster ip addresses.

The sentence above is very confusing. Perhaps I missed something. Why are you moving SAMBA$ROOT?

>Can we simply define another common cluster >alias for all 4 IA64-nodes?

I don't understand what is wrong with your current cluster alias?

Brad McCusker
Software Concepts International
www.sciinc.com

Re: Samba in cluster with different TCP/IP subnets

Michael Menge — Mon, 22 Nov 2010 13:39:47 GMT

Sorry for late answer, I was on holiday.

1. Correct, 5 different CIFSs installations.

Users are connected usually to the netbios alias LE_C and could manually switch to LN_C if no server behind LE_C is reachable.
For automatically failover we want to create a clusterwide resouce. To do it, we could backup one of the 5 CIFS installations to a shadow set between location LE and LN (or install CIFS new) and change some parameters of the smb.conf file.
Can we add another clusterwide netbios alias name to the smb.conf file? Could a CIFS installation be spanned over servers being in different subnets?
Today automatically failover is only between the 2 servers at location LE and the 2 at location LN but not between location LE and LN.