Hello, I've been using UML for production servers for years, but I'm now experiencing some performance problems with UBD (I've always used it with CONFIG_BLK_DEV_UBD_SYNC).
I tried to patch UBD to run several I/O threads that perform the requests in parallel. It improved performances significantly, but not enough for me. Using UML without CONFIG_BLK_DEV_UBD_SYNC improves performance a lot, but the the guest has no way to ensure that it's data is actually written on the disc. I certainly don't wan this for, e.g., a mail server, or my users will kill me. I read that there used to be some work done about using AIO for UBD, with the device file opened with O_DIRECT. As far as I can see, it lokks exactly like what I need. I read that Jeff reverted the change just before 2.6.14, but he was then saying that he would re-add it soon... What's the status of UBD with AIO nowadays? Does anyone use it? Where can I find a patch that implements this? Regards, Nicolas ------------------------------------------------------------------------------ Open Source Business Conference (OSBC), March 24-25, 2009, San Francisco, CA -OSBC tackles the biggest issue in open source: Open Sourcing the Enterprise -Strategies to boost innovation and cut costs with open source participation -Receive a $600 discount off the registration fee with the source code: SFAD http://p.sf.net/sfu/XcvMzF8H _______________________________________________ User-mode-linux-user mailing list User-mode-linux-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user
