Christian Brandes
2007-Oct-12 14:52 UTC
[Samba] static wins entries for failover shares -- do Microsoft clients get confused?
On my RedHat Cluster I am trying to configure samba shares that can be relocated or fail over from one node to anoter. This is done by: 1. mounting the corresponding file system on the node from SAN 2. having the cluster assign the corresponding virtual ip number to that node 3. I tried to run an aditional instance of samba for that share ( See posting: "security = domain -- samba adds its netbios name as samba domain to LDAP") As I ran into trouble with such a lot samba instances beeing safely started and stopped on one machine, now I try another method: I try to run only one instance of samba on each node and then work with: "netbios alias =" and "include =" It is not possible to add all needed netbios aliases to all nodes because then all nodes seem to have the same names and clients get confused, trying to resolve names and having to wait for some timeout. I do not know what happens in detail. What I know is that sometimes it takes a long time to establish a file transfer, but when it is established, it has full bandwidth. So it is more some kind of latency. This meens processes that open a lot of files can drastically slow down. So I looked for the solution in the use of wins. I eliminated "netbios aliases" in smb.conf. Instead I introduced "Static WINS Entries" as stated in Samba-3-Howto like that: "SERVER1#00" 0 192.168.1.1 192.168.1.1 66R "SERVER1#20" 0 192.168.1.1 192.168.1.1 66R "SERVER1#03" 0 192.168.1.1 192.168.1.1 66R Which is the netbios name of my one of my servers with it's two physical ip numbers on it's network interfaces. "SHARE1#00" 0 192.168.1.41 192.168.1.41 66R "SHARE1#20" 0 192.168.1.41 192.168.1.41 66R "SHARE1#03" 0 192.168.1.41 192.168.1.41 66R Which is the former netbios alias associated with the two virtual ip numbers that are assigned to the node that actually holds the corresponding share. The share should be accessible by: \\SHARE1\share1 Distinguished is by "include = /etc/samba/smb.conf.%i". So that works fine. Name resolution is done by wins real quickly. For some reason a DNS query as well is done by Microsoft Clients even when the name is resolved by wins. And hybrid clients even do a broadcast after they got their wins reply. For some reason after a while Microsoft clients still get confused. Maybee when they get a wins reply, then broadcast and get a different one from the server. This affects even file transfer to Novell Clients, which sometimes have this latency, too. So it must be a blocking wait for a timeout. ( See posting: multihomed samba -- how to tell samba which ip-numbers to respond? ) Does anyone know why Microsoft clients get confused? Or even better how to configure a cluster with samba shares that fail over from one node to another? Best regards Christian