Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
nfs (udp-based nfs is stateless) - that means if the nfs serving node fails over, the clients access to that share will freeze briefly and then continue where they were (open files will remain open, programs executed from the filesystem will continue to run) smb (the file sharing protocol which samba implements) is statefull - this means that if the samba server node fails over, the client may/will report an error (since the actual connection between the client and the server is broken - samba gets started on the second node but this will be a new connection which the client must issue a retry against). How this is handled is up to the client. There are no mainstream platforms which offer session failover for smb as far as i know - maybe vms clustering could work some magic but thats about it. Microsoft clustering of file shares has exactly the same problem. the problem is not that the file will not be mirrored, but that the clients' connections to the server will break and need to be restarted/retried (manually or maybe automagically by the application). this may or may not be visible to the user - it depends on the platform (windows version) and the application. it is necessary that the samba tdb files (which contain a record of client locks and other "stateful" information) be on the replicated disk, to ensure the second node can read them when it is failed over to. In a failover situation, I think these are somewhat analogous to the nfs server's rmtab files. you can share out the same directories via samba and nfs. be aware that your server platform may or may not synchronise locking between these two sharing technologies (linux and irix will, probably freebsd too). the configuration of the sharing of these directories will be maintained separately: nfs in /etc/exports, samba in /etc/smb.conf the samba and nfs HA resources will both have the same disk resource associated with them (the drbd device in this case) see the notes at the end of this page for more info: http://www.redhat.com/docs/manuals/enterprise/RHEL-AS-2.1-Manual/cluster-manager/s1-service-samba.html admin On Thursday 01 June 2006 17:46, Philippe Rousselot wrote: > Hello > > I want to make a samba HA system. The reason I do not use NFS is the > presence of a few windows machines in the network. > > I spent some time reading the archives and I have a few points to > clarify. > > > There are no problems having a NFS HA system using DRBD and heartbeat, > but samba not being state-less there maybe some error during the > mirroring. > > This error can be overcome by retrying. > > what do it mean ? > > someone save a file and it is not mirrored ? > > but it will be at some point ? > > do I need to survey the system and do something when there is an error > or is there an automatic system that will solve the problem at some > point ? > > is this error visible directly from the client under windows ? > > is it possible to have a system sharing NFS and Samba properties ? I > have a folder and when I use a linux client I use samba ad when I use a > windows client I use samba. as I have a NFS share, the problem is > solved ? > > sorry if these question seems trivial. > > Thanks for you help > > > Philippe > > > > -- > Philippe Rousselot <prousselot at alcatorda.com>