Locking with CTDB

[Henning Henkel]

Volker Lendecke schrieb:
>
> No, that is a bug in OCFS2. Cifsmount->Samba uses the Posix
> extensions, and in this case Samba just passes the posix
> lock requests down to the file system. We do not do the
> Posix locking semantics on our own in this case. You might
> want to try "unix extensions = no" on the Samba server, but
> I am not sure that cifsfs is able to map the app's unix
> locks correctly to Windows locks. If it does, you get the
> mapped locks correctly handled across the cluster.
>
> Volker
>   
Okay, after a hard time debugging while it still doesn't work with 
Windows clients, I watched one of Andrew Tridgell's movies, which gave 
me the final clue. I came accross the 'vfs objects = fileid' option for 
smb.conf file, and a look into the source revealed that "fileid:mapping" 
apparently has been renamed to "fileid:algorithm" in Samba 3.2.

Incidentially, the fs I've been toying around with happens to be 
Frauenhofer's clustered filesystem (FhGFS) which does not support Posix 
locks and, even worse,  does not provide consistent inode numbers across 
different fs clients. So it's a nice example of what can go wrong when 
trying to run clustered Samba, but it's definitely not up to the job. (I 
also happened to note that the same inconsistencies in inode numbers 
happen for multiple cifsmounts of the same share even from a single 
server. Does that happen by design or is it a bug?)

Maybe it would be good to have some information at the wiki which 
versions of Samba and CTDB are used in the examples?

Henning

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