Ah, thanks. I rebuilt it with sync off, and the performance jumped up to something close to the host one. Would that actually put ext4 guest fs in any danger in case of a crash?
Sadly, it developed that the 64bit UML can't run 32bit programs, which is a deal breaker to me. While it's something that was working at one point and apparently also fixable with some effort, the sum total of problems makes qemu-kvm look more attractive in the end. It's peculiar to see UML in such a state of disrepair - for a long while i thought it was a widely used lean virtualization platform, powering things like containers, docker and so on. Some research and disillusionment later, i'm left wondering what went wrong. Even the ultra-useful Windows port, CoLinux, seems to be abandoned. In any case, good luck with the patches! > 2016-07-09 1:15 GMT+03:00 > <user-mode-linux-devel-requ...@lists.sourceforge.net>: > Check if you have sync turned on. > > Form of async IO - very similar to what posix async IO implementations > do. If done correctly it can speed up things quite a bit. For it however > actual files need to be opened async. The number you quoted makes me > think you have sync enabled (it is enabled in some distros by default > via kernel config options). ------------------------------------------------------------------------------ Attend Shape: An AT&T Tech Expo July 15-16. Meet us at AT&T Park in San Francisco, CA to explore cutting-edge tech and listen to tech luminaries present their vision of the future. This family event has something for everyone, including kids. Get more information and register today. http://sdm.link/attshape _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel
