Re: [Libguestfs] virt-sparsify failed (was: [oVirt Jenkins] ovirt-system-tests_basic-suite-master_nightly - Build # 479 - Failure!)

On Wed, Oct 14, 2020 at 8:54 AM Yedidyah Bar David <didi(a)redhat.com&gt; wrote: > > On Tue, Oct 13, 2020 at 8:40 PM Richard W.M. Jones <rjones(a)redhat.com&gt; wrote: > > > > On Tue, Oct 13, 2020 at 07:56:29PM +0300, Nir Soffer wrote: > > > On Tue, Oct 13, 2020 at 7:15 PM Richard W.M. Jones <rjones(a)redhat.com&gt; wrote: > > > > > > > > On Tue, Oct 13, 2020 at 06:45:42PM +0300, Nir Soffer wrote: > > > > > I think this is the right solution - when virt-something tool fails, > > > > > it should log the reason for the failure - the error that caused the > > > > > tool to fail. I'm not sure this is easy to do as the failing code > > > > > run inside a special VM. Maybe the code running in the VM should log > > > > > the output in a machine readable way, so once an error is detected > > > > > virt-something can report the error as the reason, without running > > > > > in debug mode. > > > > > > > > All the virt-* tools that I've written have a non-zero exit code and > > > > print an error message on stderr when they fail. Errors from inside > > > > the appliance are propagated to the library and thence to the tool > > > > correctly. > > > > > > > > I think the best thing to do is: > > > > > > > > - spool up stdout + stderr from the tool > > > > > > > > - if the exit code != 0, save the spooled output for analysis > > > > > > > > - if the exit code == 0, discard it (or keep it if you like) > > > > > > This is what we already do, and the result is not helpful. If you look > > > at the log message in the previous message, basically the only > > > info about the error is: > > > > > > libguestfs error: guestfs_launch failed > > > > > > I don't see what we can do with this error message. > > > > Right, so in this particular instance the error message would tell us > > that you should run libguestfs-test-tool because your qemu/kernel/etc > > is broken in some way :-/ > > > > There's not a particularly good answer here if you don't want to ever > > use LIBGUESTFS_DEBUG/LIBGUESTFS_TRACE, but perhaps you could run > > libguestfs-test-tool if you see any error which matches the substring > > /guestfs_launch/ ? > > Another (orthogonal?) option: > > Make LIBGUESTFS_DEBUG/LIBGUESTFS_TRACE log elsewhere, not to stdout/err > (e.g. some other file descriptor, or to a file passed via env or whatever). > This way, it might make sense for vdsm to always pass these vars, continue > logging all stdout/err, and log/keep debug/trace logs only on errors. This now happened again: https://jenkins.ovirt.org/job/ovirt-system-tests_basic-suite-master_night... https://jenkins.ovirt.org/job/ovirt-system-tests_basic-suite-master_night... 2020-11-09 01:05:42,031-0500 INFO (jsonrpc/4) [api.host] FINISH getAllVmIoTunePolicies return={'status': {'code': 0, 'message': 'Done'}, 'io_tune_policies_dict': {'c189ecb3-8f2e-4726-8766-7d2d9b514687': {'policy': [], 'current_values': [{'name': 'vda', 'path': '/rhev/data-center/mnt/192.168.200.4:_exports_nfs_share1/1d093232-d41e-483f-a915-62f8db3c972f/images/e7ee6417-b319-4d84-81a5-5d77cbce2385/710d2c10-e6b7-4d16-bd37-50a9d4e14a80', 'ioTune': {'total_bytes_sec': 0, 'read_bytes_sec': 0, 'write_bytes_sec': 0, 'total_iops_sec': 0, 'write_iops_sec': 0, 'read_iops_sec': 0}}]}}} from=::1,34002 (api:54) 2020-11-09 01:05:42,038-0500 DEBUG (jsonrpc/4) [jsonrpc.JsonRpcServer] Return 'Host.getAllVmIoTunePolicies' in bridge with {'c189ecb3-8f2e-4726-8766-7d2d9b514687': {'policy': [], 'current_values': [{'name': 'vda', 'path': '/rhev/data-center/mnt/192.168.200.4:_exports_nfs_share1/1d093232-d41e-483f-a915-62f8db3c972f/images/e7ee6417-b319-4d84-81a5-5d77cbce2385/710d2c10-e6b7-4d16-bd37-50a9d4e14a80', 'ioTune': {'total_bytes_sec': 0, 'read_bytes_sec': 0, 'write_bytes_sec': 0, 'total_iops_sec': 0, 'write_iops_sec': 0, 'read_iops_sec': 0}}]}} (__init__:360) 2020-11-09 01:05:42,435-0500 DEBUG (tasks/3) [common.commands] FAILED: <err> = b"virt-sparsify: error: libguestfs error: guestfs_launch failed.\nThis usually means the libguestfs appliance failed to start or crashed.\nDo:\n export LIBGUESTFS_DEBUG=1 LIBGUESTFS_TRACE=1\nand run the command again. For further information, read:\n http://libguestfs.org/guestfs-faq.1.html#debugging-libguestfs\nYou can also run 'libguestfs-test-tool' and post the *complete* output\ninto a bug report or message to the libguestfs mailing list.\n\nIf reporting bugs, run virt-sparsify with debugging enabled and include the \ncomplete output:\n\n virt-sparsify -v -x [...]\n"; <rc> = 1 (commands:98) I suggest that if we have come to a dead-end and no-one has any clue, then we either patch something (vdsm?) to allow getting more information if this happens again, or open a bug for further discussion/prioritization.