On Wed, 2 Mar 2005, Nuutti Kotivuori wrote: > If swap is enabled for a virtual machine, and the virtual machine > actually swaps something, swapoff at shutdown hangs the machine.
Here's another nasty hang that I first blundered into last night, which probably is unrelated but which might be helpful. The default max size of tmpfs is half your physical memory. If the UML RAM image is in tmpfs, and is configured larger than this (remember to leave space for inodes and for other clients like KDE), and you make it use the RAM, the machine sounds like it's swapping a bunch of stuff, and UML pretty quickly gets a "kernel mode signal 7", SIGBUS, which is logical when you think about it. So don't do that. If all your tmpfs's add up to more than your swap space plus physical memory, and you fill them up, then the *host* will get a kernel panic. So don't do that either. This came up when I was doing an online update of my UML's distro, which used a lot of I/O buffers. When I limited the configured RAM size to fit in tmpfs, the online update was finished with no problems. Swapoff did not hang the machine. But I can't be sure whether the UML swapped anything; I kind of doubt it. James F. Carter Voice 310 825 2897 FAX 310 206 6673 UCLA-Mathnet; 6115 MSA; 405 Hilgard Ave.; Los Angeles, CA, USA 90095-1555 Email: [EMAIL PROTECTED] http://www.math.ucla.edu/~jimc (q.v. for PGP key) ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click _______________________________________________ User-mode-linux-user mailing list User-mode-linux-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user
