Oracle in NT and file locks

I'm new-ish to Oracle on NT (UNIX & VMS background) this was news to me and got me out of bed last night. So I thought I'd share it with the list. Apologies if it is old-hat or irrelevant but the consequences are serious if you do not realise how Oracle locks any of its files under NT (and that includes redo logs and control files as well as database files). This is a snip from WWS:

<SNIP>

On NT Oracle does not lock any of the files (datafiles, redolog files, controlfiles etc). There is a "shared lock", you cannot delete files of a running database, but other processes can go in and lock parts of files as well. That's the way it has been designed and nothing can or will be done about that.

Problems start when other programs take locks on pieces of the database files that we try to write to (eg backup software other than NT backup command but it could be ANYTHING).
</SNIP>

In my case Veritas backup exec had been configured incorrectly and was taking write locks on my duplexed redo logs and control files. Oracle fell over in a horrible mess (ora-600s, dropped threads, no ability to connect even as internal) and the only solution was to restart NT. Received on Thu Nov 23 2000 - 03:42:54 CST