On Mon, Nov 9, 2020 at 11:03 AM Richard W.M. Jones <rjones@redhat.com> wrote:
On Mon, Nov 09, 2020 at 09:16:33AM +0200, Yedidyah Bar David wrote:
On Wed, Oct 14, 2020 at 8:54 AM Yedidyah Bar David <didi@redhat.com> wrote:
On Tue, Oct 13, 2020 at 8:40 PM Richard W.M. Jones <rjones@redhat.com> 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@redhat.com> 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_nightly/...
https://jenkins.ovirt.org/job/ovirt-system-tests_basic-suite-master_nightly/...
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.
You definitely need to run libguestfs-test-tool from vdsm if we're going to get any further with this.
Now filed [1] on vdsm. Feel free to comment there about what else we should do to get more information. Thanks! [1] https://bugzilla.redhat.com/show_bug.cgi?id=1895843 Best regards,
Rich.
-- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-p2v converts physical machines to virtual machines. Boot with a live CD or over the network (PXE) and turn machines into KVM guests. http://libguestfs.org/virt-v2v
-- Didi