Hide Forgot
Description of problem: Improve the error info when do blockpull on same source file Version-Release number of selected component (if applicable): libvirt-0.10.2-46.el6.x86_64 How reproducible: 100% Steps to Reproduce: 1. Prepare a running guest # virsh list Id Name State ---------------------------------------------------- 3 rh6.5 running 2. Create one external disk-only snapshot # virsh snapshot-create-as rh6.5 s1 --disk-only Domain snapshot s1 created 3. Do blockpull with base point to current "source file" # virsh dumpxml rh6.5|grep "source file" <source file='/var/lib/libvirt/images/kvm-rhel6.5-x86_64-qcow2.s1'/> # virsh blockpull rh6.5 vda --base /var/lib/libvirt/images/kvm-rhel6.5-x86_64-qcow2.s1 error: internal error Unexpected error Actual results: Expected results: Libvirt should post more clear error info stead of "Unexpected error" Additional info:
Upstream commit: commit 3e3c6ff10fdb0bb086d61629d75bcad9169152b9 Author: Eric Blake <eblake@redhat.com> Date: Wed Jun 11 16:22:57 2014 -0600 blockcommit: require base below top The block commit code looks for an explicit base file relative to the discovered top file; so for a chain of: base <- snap1 <- snap2 <- snap3 and a command of: virsh blockcommit $dom vda --base snap2 --top snap1 we got a sane message (here from libvirt 1.0.5): error: invalid argument: could not find base 'snap2' below 'snap1' in chain for 'vda' Meanwhile, recent refactoring has slightly reduced the quality of the libvirt error messages, by losing the phrase 'below xyz': error: invalid argument: could not find image 'snap2' in chain for 'snap3' But we had a one-off, where we were not excluding the top file itself in searching for the base; thankfully qemu still reports the error, but the quality is worse: virsh blockcommit $dom vda --base snap2 --top snap2 error: internal error unable to execute QEMU command 'block-commit': Base '/snap2' not found Fix the one-off in blockcommit by changing the semantics of name lookup - if a starting point is specified, then the result must be below that point, rather than including that point. The only other call to chain lookup was blockpull code, which was already forcing the lookup to omit the active layer and only needs a tweak to use the new semantics. This also fixes the bug exposed in the testsuite, where when doing a lookup pinned to an intermediate point in the chain, we were unable to return the name of the parent also in the chain. * src/util/virstoragefile.c (virStorageFileChainLookup): Change semantics for non-NULL startFrom. * src/qemu/qemu_driver.c (qemuDomainBlockJobImpl): Adjust caller, to keep existing semantics. * tests/virstoragetest.c (mymain): Adjust to expose new semantics. Signed-off-by: Eric Blake <eblake@redhat.com> v1.2.5-133-g3e3c6ff
Verified with libvirt-1.2.17-2.el7.x86_64 and qemu-kvm-rhev-2.3.0-12.el7.x86_64. Steps 1. define/start a vm with following xml <disk type='file' device='disk'> <driver name='qemu' type='qcow2'/> <source protocol='gluster' name='gluster-vol1/rhel7.qcow2'> <host name='10.66.4.164' port='24007'/> </source> <target dev='vda' bus='virtio'/> </disk> 2. create 3 snapshots # for i in {1..3}; do virsh snapshot-create-as vm3 s$i --disk-only --diskspec vda,file=/tmp/vm3.s$i; done Domain snapshot s1 created Domain snapshot s2 created Domain snapshot s3 created 3. do blockpull by specifying base with top image # virsh blockpull vm3 vda --base /tmp/vm3.s3 --wait --verbose error: invalid argument: could not find image '/tmp/vm3.s3' beneath '/tmp/vm3.s3' in chain for '/tmp/vm3.s3'
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://rhn.redhat.com/errata/RHBA-2015-2202.html