NFSv3 and NFSv4?

[RegularJoe]

Hi All,

I am wondering how file locking works with a FreeNAS server that allows NFSv3 clients to connect when it primarily serves NFSv4? If the users try to work on the same file is this a train wreck? Is there a way to allow NFSv3 as read only if there is no way to avoid file locking issues?

Thanks,
Joe

 

[dlavigne]

Did you find the answer to your question?

 

[RegularJoe]

not yet, I might have to post in a freeBSD forum or Linux one.

 

[rvassar]

NFSv3 doesn't support locking as part of the protocol. That's the crux of the problem. It's a "bolt on" implemented differently by different vendors. NFSv4 incorporates it as part of the protocol. But on FreeNAS, there doesn't appear to be a "lslk" binary like Solaris 10...

 

[RegularJoe]

yes, it seems that even NFSv3 on Linux can have mixed locking mechanisms, I recall a service called portmap, I did not realize how large a bag of worms file locking is on NFSv3. :-( sounds like NFSv4 fixes everything, or at least on CentOS it does. LOL

https://www.centos.org/docs/5/html/Deployment_Guide-en-US/ch-nfs.html