In message <20090208200204.0679b...@il130.idmt.fraunhofer.de>, Johannes Hirte writes:
> It seems to be distribution specific. I've tested with gentoo > (unstable) now, and it works well. Testcase was a ro mounted local > filesystem together with a rw mounted tmpfs. No problems so far. Tested > with linux-2.6.28.4 + unionfs-2.5.1. If the same kernel and same config behave differently on different distros, then the culprit may be glibc or utilities like /bin/cp. > > 1. What can you tell me about your NFS server? What OS and OS > > version is it? What version of the NFS proto do you use (2? 3? 4?) > > and what transport (udp? tcp)? I'll try to reproduce the conditions > > exactly on my end. > > The server is Mandriva 2007.0 based, the client is 2008.1 based. > NFS-Version 3 with tcp is used. But I'm not sure that NFS is the reason > for the problems. It's a remote possibility, but I'd like to cover all bases. The NFS client interprets NFS_ERR codes from the server, and the server tries to map errno's it got from the exported filesystem into NFS_ERR codes. There are all kinds of odd conditions such as combinations of a read-write mounted NFS volume from the client, which is exported ro by the server; or a rw export of a ro mounted f/s. I've seen cases in which various errors get munged and by the time they get to unionfs, they don't reflect the true nature of the issue. For example, if an nfs client and/or server converts an EROFS to EPERM, unionfs may *not* copyup such a file b/c it'll violate permissions. When you do your tests, it might be helpful to tcpdump and check what kinds of NFS-level messages and errors are being passed on the network. > > 4. Any chance I can get a temp ssh access to a system you have that > > demonstrates this? In my experience, a 5 minute poking around a > > system can save everyone many hours/days of emails and attempts to > > second guess each other. > > I will try to find a system we can make accessible outside from our > network. An alternative is to give me VMware Player/Workstation images, pre-installed w/ the problematic distros and kernels. I'll try your kernel configs and see if they made a difference on my end. Thanks, Erez. _______________________________________________ unionfs mailing list: http://unionfs.filesystems.org/ unionfs@mail.fsl.cs.sunysb.edu http://www.fsl.cs.sunysb.edu/mailman/listinfo/unionfs
