On Tue, Sep 28, 2010 at 05:34:37PM -0400, Andy Liebman wrote: > I can tell you that setting write cache size to 131072 (half the > size) makes the corruption go away, and so does turning off the > "write cache size" setting altogether. However, we are now > wondering why the "write cache size" can have this effect on file > corruption and whether setting it to 131072 will cause a corruption > problem under some other circumstance we just haven't hit yet.
Well it's because this code must have a bug :-). Volker is right, you should check it first with the v3-6-test git tree code, as he has done some changes there that might have already fixed it (if so we will back-port to 3.5.next of course). If not, we'll need voluminous traces to track down the exact set of writes that cause the problem. Using the vfs_full_audit might initially help. > Any ideas? By the way, we have seen and documented this problem > with both Samba 3.4.2 and Samba 3.5.3. We also noticed that "write > cache size" was listed as "deprecated" in 3.4.2 and that in 3.5.3 it > is no longer listed as "deprecated". Somebody besides us must have > thought keeping "write cache size" was still a good idea?? I wrote the original "write cache" code but thought it wasn't needed (so marked it deprecated) but as Volker found, sometimes it's really useful in certain workloads. Jeremy. -- To unsubscribe from this list go to the following URL and read the instructions: https://lists.samba.org/mailman/options/samba
