Description of problem: On a recently cleanly installed machine with 2Gb of memory the xenguest-install.py bombs out with the message Error: Error creating domain: I need 257 MiB, but dom0_min_mem is 256 and shrinking to 256 MiB would leave only 1254 MiB free. Version-Release number of selected component (if applicable): xen-3.0.1-4 kernel-xen0-2.6.16-1.2080_FC5 kernel-xenU-2.6.16-1.2080_FC5 How reproducible: every time Steps to Reproduce: 1. install FC5 / add xen rpms and dependencies manually 2. use yum to upgrade any fixes 3. boot into xenU0 / standard kernel options from install 4. run /usr/sbin/xenguest-install.py and answer as follows What is the name of your virtual machine? test4 How much RAM should be allocated (in megabytes)? 256 What would you like to use as the disk (path)? /scratch/systems What is the install location? http://ftp.ussg.iu.edu/linux/fedora/linux/core/5/i386//os/ Actual results: Starting install... Using config file "/etc/xen/test4". Error: Error creating domain: I need 257 MiB, but dom0_min_mem is 256 and shrinking to 256 MiB would leave only 1254 MiB free. If your install has exited, you can restart your guest by running 'xm create -c test4'. Otherwise, you can reconnect to the console by running 'xm console test4' no guest system is created in /scratch/systems Expected results: working xenU installation created / no error output. Additional info: 2GB Thinkpad R51. This seems to be similar to Bug 184393 but I'm posting it as a new bug since it's in the new/current software version. I haven't yet tried with selinux turned off, but I will reboot just after filing this info. xm mem-set 0 xxx seems to work fine.
Turning of selinux with "setenforce 0" has no effect whatsoever. Booting with "kernel /xen.gz-2.6.16-1.2080_FC5 dom0_mem=512M" in /etc/grub.conf seems to fix this problem. Looking at "xm top" it seems as if memory allocated to domain 0 never falls, even if "xm mem-set 0 512" is used. At this point the installation continues on to crash at a later point.
xend is doing a backwards comparison... I remember seeing the patch fly across xen-devel a week or two ago
Built a couple systems (one x86_64 one i386) and this problem seemed confined to i386 version for some bizarre reason.
The problem of the backwards memory comparison was fixed in the 3.0.3 release of Xen. Since FC5 is now on xen-3.0.3-2.fc5, this ticket is resolved.