Hi, I've been using uml on production servers for months, and have been quite happy with it, except for I/O performance.
I was using the user-mode-linux package from Debian Etch, based on 2.6.18, and compiled with CONFIG_BLK_DEV_UBD_SYNC. Disabling this option of course helps performance, but I feel that it's somewhat unsafe if the host crashes... Moreover, I don't think it helps read performance. As far as I can see, if one wants both safety and performance, the I/O must not be serialized. So I decided to give it a try. The first step was to run a per-device I/O thread. This improves slightly the performance with several UBD devices: I/O on one device do not block I/O on another device. Moreover, that helps to implement parallelized I/O. Then I managed to run several parallel threads per device. As far as I am concernced, that much improves the performance. But currently, my code is more a dirty proof-of-concept than a clean patch. Would you be interested by my work? Cheers, Nicolas Boullis École Centrale Paris ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel
