HP StorageWorks 9100 Extreme Data Storage System administration guide V1.0.2 (AN540-96018, February 2010)

The backup server for one virtual Samba server can be the primary server for another virtual server.
Also, a server blade can broadcast multiple PSFS filesystems. The only restriction is that each PSFS
filesystem can be associated with only one virtual Samba server.
A virtual host IP address used by Samba cannot be used as a VNFS or VHTTPD virtual host.
Use of the configuration files
The Samba smb.conf file determines what is shared and how it is shared. The Samba solution breaks
smb.conf into an smb.default file and one or more smb.conf.<virtual—host> files.
When a client requests share access via a virtual Samba server, the smb.conf file is constructed
dynamically from the smb.default and smb.conf.<virtual–host> files.
• If no virtual Samba servers are hosted on a server, the smb_meth script overwrites the smb.conf
file with smb.default.
• If one or more virtual Samba servers are hosted on a server at the time of the client request, the
smb_meth script dynamically modifies the smb.conf file to specify the valid virtual Samba
server names hosted by the server and to include the appropriate smb.conf.<virtual–host>
file.
Consequently, only the smb.default and smb.conf.<virtual-host> files should be modified.
The smb.conf file should be managed by the smb_meth script because any changes made directly
to the file can be overwritten during a failover. Additionally, changes to the smb.default file are
not reflected on a given server until all of its virtual Samba servers have been failed-off the server (that
is, the smb.conf file is overwritten).
All servers (primary or backup) that can host a virtual Samba server must have identical smb.default
and smb.conf.<virtual–host> files at all times. If you do not use symbolic links as described
below, the administrator must manage this manually, since it is not an automated process.
Considerations for deploying Samba with HP ExDS9100
Before configuring Samba, review the following considerations:
• This configuration is not a replacement for large-scale Windows File Serving deployments. The
maximum number of users for a Samba server is 200 active users per server. The HP ExDS/Samba
solution has been tested with several hundred users in a high-stress mode and is stable and re-
sponsive. However, some workloads may be significantly more taxing for the server than others.
If your site is planning a large client workload for the Samba cluster, HP recommends that you
contact HP consulting for specific configuration help.
• The ACL feature provided with Windows File Serving is not supported.
• The virtual Samba server may affect the performance of other applications on your cluster servers,
depending on how heavily the Samba server is used. Although there are no specific guidelines
for determining how a server may be affected based on workload, you should be aware of this
potential impact and should monitor performance when users begin accessing the Samba server.
• This solution makes Samba highly available, but it is not a scale-out configuration. Samba itself
is not designed to share the same data from multiple servers at the same time, and this solution
does not address this Samba limitation.
• Opportunistic Locking (oplocks) are turned on by default. They can be turned off, which may im-
prove performance for some workloads.
• If the Samba solution is deployed in a large enterprise Windows server environment (with many
Windows servers on the same network as the Samba cluster), the administrator should turn off the
Master Browser ability for all but one server in the cluster. (The Samba solution does not default
Managing data70