Red Hat Bugzilla – Bug 1263782
noVNC console on Openstack Dashboard is rendering garbled UI on RHEL7
Last modified: 2016-04-25 16:45:36 EDT
Created attachment 1074135 [details]
Description of problem:
I am running openstack nova-compute on RHEL7 and RHEL7.1. Openstack dashboard's noVNC console is rendering garbled UI for any instance having a UI console. This is working just fine on RHEL65
100% of the times
Steps to Reproduce:
1.Provision an instance with openstack. The instance should have a desktop (e.g. Windows)
2. Open VNC Console on Horizon dashboard
3. UI is rendered with BLACK Strips and is not readable.
UI rendered is totally garbled and is unreadable.
UI should be clear.
This does work perfectly on RHEL6.5
Possibly bug 1247479 duplicate.
Can you double-check whevener this really is vnc?
There is a web client for spice too.
Anyway, I can't imagine how this could be a libvirt issue. Moving to qemu-kvm-rhev for now.
Abhishek, thanks for taking the time to enter a bug report with us. We use reports like yours to keep improving the quality of our products and releases. That said, we're not able to guarantee the timeliness or suitability of a resolution for issues entered here because this is not a mechanism for requesting support.
If this issue is critical or in any way time sensitive, please raise a ticket through your regular Red Hat support channels to make certain it receives the proper attention and prioritization that will result in a timely resolution.
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@Gerd Hoffman, thanks for your quick response and looking into this.
The client is noVNC. It's an openstack setup and nova-novncproxy service uses noVNC as the default client. And the problem just occurs on any guest running a desktop on it (not necessarily windows)
I tried experimenting with decreasing the VRAM to 9126 which was earlier the default for RHEL65 (actually now it has to be in powers of 2 so I made it 8192) thinking that 16MB would be huge data to be rendered on the browser canvas, but that didn't help.
I have got both RHEL65 and RHEL71 and it does work for RHEL65.
@Ademar Reis, Thanks for pointing the direction. It's actually a time sensitive and critical stuff. Our support matrix has got RHEL71 and we desperately need atleast a workaround to make the VNC console usable.
I will post the bug to your Red Hat production support team as well.
Ok, novnc is buggy. Bisected to "6940936 WIP: Switch to Pako for zlib".
Whom should this be reassigned to?
I'm moving this BZ to the novnc component, under Red Hat Open Stack product.
Abhishek: I hope the support team is able to assist you (please refer them to this BZ if you haven't done so yet). As pointed out by Gerd above (comment #6), novnc appears to be broken and the commit that introduced the issue is "6940936 WIP: Switch to Pako for zlib".
But keep in mind that noVNC is not a supported package in RHEL7 (I don't know if your subscription covers only RHEL or Red Hat OpenStack). For RHEL7, noVNC is part of EPEL, which is community supported.
This commit should fix the issue -- please let me know if it does (sorry for the delayed response): https://github.com/kanaka/noVNC/pull/532
Works like a charm :)
Thanks a ton @Sally Ross.
It appears this bug was introduced (and later fixed) in upstream code after v0.5.1, the version included in Red Hat OpenStack Platform: