Red Hat Bugzilla – Bug 736590
Improve error message when migration fails due to stopped libvirtd on the target
Last modified: 2018-02-15 19:34:02 EST
Description of problem: Error is not clear when migrate but libvirtd is not started on target host Version-Release number of selected component (if applicable): libvirt-0.9.4-10.el6.x86_64 qemu-kvm-0.12.1.2-2.188.el6.x86_64 kernel-2.6.32-193.el6.x86_64 How reproducible: everytimes Steps to Reproduce: On target host: 1. stop libvirtd # service libvirtd status libvirtd is stopped On source host: 1. start a guest with shared nfs image 2. migrate from source to target host: # virsh migrate vr-rhel6-x86_64-kvm --live qemu+ssh://10.66.85.218/system Actual results: # virsh migrate vr-rhel6-x86_64-kvm --live qemu+ssh://10.66.85.218/system root@10.66.85.218's password: error: End of file while reading data: : Input/output error Expected results: I think the following error prompt is more clear: # virsh migrate vr-rhel6-x86_64-kvm --live qemu+ssh://10.66.85.218/system error: End of file while reading data: : Input/output error error: failed to connect to the hypervisor Additional info:
This is nothing specific to migration, you'll get the same error message just with $ virsh -c qemu+ssh://root@localhost/system root@localhost's password: error: End of file while reading data: : Input/output error error: failed to connect to the hypervisor It is not entirely trivial to improve on this due to the way remote SSH tunnelling works.
This should become better once we have a libssh2 transport (covered by bug 513363). Although nc is unhelpful and doesn't provide any error message when it can't connect to a unix socket. Fortunately, it sets it's return code to 1 in that case. Using libssh2 we can see this return code (and can distinguish it from ssh connection failure, which we can't when exec'ing ssh) and provide a better error message.
There's a possibility that this could be fixed even without the libssh2 driver support. Leaving it open for investigation.
This bug was not selected to be addressed in Red Hat Enterprise Linux 6. We will look at it again within the Red Hat Enterprise Linux 7 product.