Hi, Andrew. Thank you very much for your explanation. And yes, I actually wanted to mean BDB, instead of DBD. I just checked BDB document. It seems they maintain their own locks. So my two cases will lead to data corruption. I wonder if there are any database management systems implementing locks through filesystem interface. I guess using myisam with enable-external-locking option is such a case. But when runing multiple myisam & enable-locking database servers with the same NFS datadir, will there be any deadlock problems? As you mentioned, replication and cluster seem to be better choices. But in replication case, there are more than one datacopy in the system. And all updates need to be send to the master. For cluster, I guess you mean distributed database systems. Currently, I think such systems are quite expensive to get and maintain. So I wonder if it is possible to use NFS as the storage backend and to provide data consistency needed by database, so that we can increase the number of database servers easily. I do not know if this is possible or not. I would appreciate any kinds of comments. Thanks! Jiaying Zhang
--------------------------------- Do you Yahoo!? Yahoo! SiteBuilder - Free web site building tool. Try it!
