From my reading, it looks like performing “xm migrate –live
domU target_server” ought to also copy the disk image. Am I right?
When I attempt this procedure, everything looks to work
except for the image file getting moved. The command takes about 30 seconds to
complete and then “xm list” shows the domU to be gone from the old
host and running on the new host. The SSH connection to the domU also
continues to function without a hiccup. However, the disk image isn’t
located anywhere on the new server. Also, the xen log on the new server lists
the following error:
[2008-05-15 19:10:21 xend 3790] ERROR (XendCheckpoint:275)
Device 51712 (tap) could not be connected.
/virt/myserver.img does not exist
Traceback (most recent call last):
File
"/usr/lib64/python2.4/site-packages/xen/xend/XendCheckpoint.py", line
273, in restore
dominfo.waitForDevices() # Wait for backends to set up
File
"/usr/lib64/python2.4/site-packages/xen/xend/XendDomainInfo.py", line
1760, in waitForDevices
self.waitForDevices_(c)
File
"/usr/lib64/python2.4/site-packages/xen/xend/XendDomainInfo.py", line
1158, in waitForDevices_
return
self.getDeviceController(deviceClass).waitForDevices()
File
"/usr/lib64/python2.4/site-packages/xen/xend/server/DevController.py",
line 145, in waitForDevices
return map(self.waitForDevice, self.deviceIDs())
File
"/usr/lib64/python2.4/site-packages/xen/xend/server/DevController.py",
line 179, in waitForDevice
raise VmError("Device %s (%s) could not be
connected.\n%s" %
VmError: Device 51712 (tap) could not be connected.
/virt/myserver.img does not exist
I then attempt to execute on the domU that accesses the disk
(“df”, for example) and the instance hangs.
Both servers are running the 64-bit version of CentOS and
using the xen packages from the yum repos. On the source server, “/virt”
is mounted on an ext3 filesystem in an LVM volume. “/virt” on the
target server is also ext3, but without LVM. Would this have any affect? The
domU config file is pretty basic:
name = "myserver"
uuid = "42db455d-17be-5288-cf89-7820ddcd0c76"
maxmem = 512
memory = 512
vcpus = 1
bootloader = "/usr/bin/pygrub"
>
>
>
vfb = [ "type=vnc,vncunused=1" ]
disk = [ "tap:aio:/virt/myserver.img,xvda,w" ]
vif = [ "mac=00:16:3e:1e:94:fb,bridge=xenbr0" ]
