How many xen guest can run parallel?we have Fedora core 8 host(dom0) and 9 Fedora caore 8 xen guest(domU) but only 8 guest run parallel when we try to run 9th guest then error comes which is return self.xd.domain_start(self.dom.getName(), paused) File "/usr/lib/python2.5/site-packages/xen/xend/XendDomain.py", line 999, in domain_start dominfo.waitForDevices() File "/usr/lib/python2.5/site-packages/xen/xend/XendDomainInfo.py", line 546, in waitForDevices self.getDeviceController(devclass).waitForDevices() File "/usr/lib/python2.5/site-packages/xen/xend/server/DevController.py", line 149, in waitForDevices return map(self.waitForDevice, self.deviceIDs()) File "/usr/lib/python2.5/site-packages/xen/xend/server/DevController.py", line 174, in waitForDevice "%s" % (devid, self.deviceClass, err))VmError: Device 51712 (vbd) could not be connected. Failed to find an unused loop deviceso how many xen guest(domU) can run parallel?There is any limitations? Get news, entertainment and everything you care about at Live.com. Check it out! _________________________________________________________________ More than messages–check out the rest of the Windows Live™. http://www.microsoft.com/windows/windowslive/ _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Mon, Feb 16, 2009 at 3:12 PM, Naveed Iqbal <naveed00786@hotmail.com> wrote:> > How many xen guest can run parallel?we have Fedora core 8 host(dom0) and 9Fedora 8 is unsupported. You''d be better of with Centos 5.2 http://fedoraproject.org/wiki/End_of_life> Fedora caore 8 xen guest(domU) but only 8 guest run parallel when we try to > run 9th guest then error comes which is > > return self.xd.domain_start(self.dom.getName(), paused) > File "/usr/lib/python2.5/site-packages/xen/xend/XendDomain.py", line 999, > in domain_start > dominfo.waitForDevices() > File "/usr/lib/python2.5/site-packages/xen/xend/XendDomainInfo.py", line > 546, in waitForDevices > self.getDeviceController(devclass).waitForDevices() > File "/usr/lib/python2.5/site-packages/xen/xend/server/DevController.py", > line 149, in waitForDevices > return map(self.waitForDevice, self.deviceIDs()) > File "/usr/lib/python2.5/site-packages/xen/xend/server/DevController.py", > line 174, in waitForDevice > "%s" % (devid, self.deviceClass, err)) > VmError: Device 51712 (vbd) could not be connected. Failed to find an unused > loop device > > so how many xen guest(domU) can run parallel?There is any limitations? >You''re hitting loop device limit, not Xen limit. You can try : - changing file: to tap:aio: on domU config line (works on Centos at least), or - add "options loop max_loop=256" to /etc/modprobe.conf, and reboot your server, or - switch to LVM or partition-backed storage for domU backend. Regards, Fajar _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Naveed Iqbal wrote:> > How many xen guest can run parallel?we have Fedora core 8 host(dom0) and > 9 Fedora caore 8 xen guest(domU) but only 8 guest run parallel when we > try to run 9th guest then error comes which is > > return self.xd.domain_start(self.dom.getName(), paused) > File "/usr/lib/python2.5/site-packages/xen/xend/XendDomain.py", line > 999, in domain_start > dominfo.waitForDevices() > File "/usr/lib/python2.5/site-packages/xen/xend/XendDomainInfo.py", > line 546, in waitForDevices > self.getDeviceController(devclass).waitForDevices() > File > "/usr/lib/python2.5/site-packages/xen/xend/server/DevController.py", > line 149, in waitForDevices > return map(self.waitForDevice, self.deviceIDs()) > File > "/usr/lib/python2.5/site-packages/xen/xend/server/DevController.py", > line 174, in waitForDevice > "%s" % (devid, self.deviceClass, err)) > VmError: Device 51712 (vbd) could not be connected. Failed to find an > unused loop device > > so how many xen guest(domU) can run parallel?There is any limitations?The limitation that you are seeing here is NOT the number of domU, but the number of LOOPBACK devices. To fix this, you should set the kernel option to allow to use more loopback devices. By the way, using loopback file devices is a very bad idea, it''s a lot slower than using LVM. Look at how to setup LVM and you will have no limitation, and it will be a lot faster. Thomas _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users