Tim Connors <tconnors@rather.puzzling.org> wrote:
The current production internal webserver with 15million files and 146,000 directories rsyncs daily to our new machine. They're identical apart from OS and the old one actually having a load and being busy. The new machine can't allocate order-1 pages when backing up despite having 11.5 out of 12GB memory free. The old machine could. But it was redhat 4 and the new one is redhat 6. Naturally, we have a case open with redhat, but if you've ever had the misfortune of doing that yourself, you'll know how futile that is.
I would suggest taking it to a kernel-oriented list, but I don't know how interested they would be if it's a Red Hat kernel rather than a mainline kernel, since RH apply extensive patches, or so I've read. I'm also wondering whether the kernel tracing frameworks would help you to track down the cause. The problem is that they aren't well documented as far as I've seen. A further problem is that if nobody reports these issues properly, they won't get fixed.