We're currently limited to 256 TAP interfaces preventing creation of guests above that limit. Upstream commits from HP. http://libvirt.org/git/?p=libvirt.git;a=commitdiff;h=8fa592e3dc2a8bbece2877dede3e212165e2814a http://libvirt.org/git/?p=libvirt.git;a=commitdiff;h=d3209478d594e18adfa880c57ea67f808bfaadc9
Created attachment 378785 [details] Remove limit on number of tap devices
libvirt-0.6.3-26.el5 has been built into dist-5E-qu-candidate with the fix Daniel
The bug has been fixed in libvirt-0.6.3-26.el5 I booted thirty-two virtual machines, each with 8 virtual nics on a x86_64 system with libvirt-0.6.3-26.el5 version, there were 256 tap devices created in total, no problem found, when I booted another more one, that's ok also for creating the number of tap devices more than 256. I did the same on libvirt-0.6.3-25.el5, when booting the 33th virtual machines, it reports error: error: Failed to start domain guest21 error: internal error Failed to add tap interface 'vnet%d' to bridge 'virbr1' : Device or resource busy virbr1 is a temporary bridge created for the bug verification.
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHBA-2010-0205.html