Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Hi all, I have two servers for a HA NFS file server pair for other application servers. It is like a configuration used by the SAP landscape concept, where app servers and db servers are on separate machines. I want to separate the data and the application servers in the network, so that no users should connect to the nfs file/data server at all. The nfs file server, acting as the data server, should be a drbd pair where the primary is mounted on /Data, with a GigaBit link for replication. It should be like a NAS making the mounted /dev/drbd0 on /Data available as a nfs share. I have tried it as far as the /Data mount, and it seems to work as a NFS share. On this /Data, there should be various directories that can be used by various app servers like a webserver on /Data/http and an erp server on Data/erp server and a Samba server on /Data/samba. The directories /Data/http, /Data/erp and /Data/samba should be avaiable via the nfs server on the drbd system to the other servers. The nfs shares should be mounted as nfs on the respective servers with all file and directory rights to be managed on the local server and not by the nfs file (drbd) server. The other app servers (Web, erp & samba) should also be pairs with heartbeat, each deriving their data from the one drbd nfs file server. I have read some documentation by Dave Dykstra "Setup of high availablity NFS servers" (http://www.linux-ha.org/HaNFS)and the article by Andre' Bonhote mentioned there (http://www.linux-magazine.com/issue/33/High_Availability_NFS_Server.pdf). I picture the Disk-array in Figure 1 in the article as the drbd pair of servers providing the disk space, in stead of a SCSI over fibre. In effect I want to apply the configuration in Figure 1 for the application servers, just that the Disk-array is provided by the drbd pair per nfs. My hesitation arises with the HINTS in the article: "NFS-mounting any filesystem on your NFS servers is highly discouraged. DaveDykstra wanted both servers to NFS-mount the replicated filesystem from the active server, and through a lot of trouble mostly got it working but still saw scenarios where "NFS server not responding" could interfere with heartbeat failovers and he finally gave up on it." Could someone make the problem perhaps clearer to a newbie please. It seems my idea has a problem here. How could I then go about realising my configuration? :-) Al