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Bug 918536

Summary:	VDSM fails to connect to guest agent within VMs with >54 character names
Product:	Red Hat Enterprise Virtualization Manager	Reporter:	Jason Dillaman <jdillama>
Component:	vdsm	Assignee:	Vinzenz Feenstra [evilissimo] <vfeenstr>
Status:	CLOSED ERRATA	QA Contact:	sefi litmanovich <slitmano>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	3.1.0	CC:	abaron, bazulay, iheim, jkt, lpeer, lyarwood, lzoubek, michal.skrivanek, pspacek, vfeenstr, yeylon
Target Milestone:	---
Target Release:	3.3.0
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:	virt
Fixed In Version:	is3	Doc Type:	Enhancement
Doc Text:	To prevent issues with the limitation on the length of paths to UNIX domain sockets, VDSM now uses the UUID of virtual machines as a unique identifier for socket names.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2014-01-21 16:05:30 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Jason Dillaman 2013-03-06 13:28:02 UTC

Description of problem:
The limit for AF_UNIX socket paths is 107 characters.  Since the VM name is utilized for naming the domain socket, if the VM name is longer than 54 characters, the full path to the domain socket will be longer than the maximum.  This prevents VDSM from communicating with the guest agent.  Scanning the VDSM logs shows the following error:

VM Channels Listener:DEBUG::2013-03-05 22:27:37,156::guestIF::79::vm.Vm::(_connect) vmId=`ced6f230-e22c-494c-bdb8-7250a7e2e683`::Attempting connection to /var/lib/libvirt/qemu/channels/user2-CADX-testing-1790e5d1-1049-4f75-b970-3db478236b08.com.redhat.rhevm.vdsm
VM Channels Listener:DEBUG::2013-03-05 22:27:37,157::guestIF::87::vm.Vm::(_connect) vmId=`ced6f230-e22c-494c-bdb8-7250a7e2e683`::Connection attempt failed: AF_UNIX path too long

Version-Release number of selected component (if applicable):
vdsm-4.9.6-45.2.el6_3.x86_64

How reproducible:
100%

Steps to Reproduce:
1. Create and start a VM with a >54 character name
  
Actual results:
VDSM logs show that it fails to connect to the guest agent's virtio-serial socket.

Expected results:
VDSM successfully connects to the virtio-serial socket of the guest OS.

Comment 1 Michal Skrivanek 2013-03-06 13:37:05 UTC

Vinzenz, you had a fine idea to solve this by using UUID and symlinks for older vdsm

Comment 2 sefi litmanovich 2013-09-03 11:08:44 UTC

Verified - bug was reproduced manually on release 3.3.0 version is12.
vdsm version: vdsm-4.12.0-92.gita04386d.el6ev.x86_64.
works fine, no such error on vdsm.log, vdsm communicates fin with the guest agent.

Comment 3 Charlie 2013-11-28 00:27:48 UTC

This bug is currently attached to errata RHBA-2013:15291. If this change is not to be documented in the text for this errata please either remove it from the errata, set the requires_doc_text flag to 
minus (-), or leave a "Doc Text" value of "--no tech note required" if you do not have permission to alter the flag.

Otherwise to aid in the development of relevant and accurate release documentation, please fill out the "Doc Text" field above with these four (4) pieces of information:

* Cause: What actions or circumstances cause this bug to present.
* Consequence: What happens when the bug presents.
* Fix: What was done to fix the bug.
* Result: What now happens when the actions or circumstances above occur. (NB: this is not the same as 'the bug doesn't present anymore')

Once filled out, please set the "Doc Type" field to the appropriate value for the type of change made and submit your edits to the bug.

For further details on the Cause, Consequence, Fix, Result format please refer to:

https://bugzilla.redhat.com/page.cgi?id=fields.html#cf_release_notes 

Thanks in advance.

Comment 4 Michal Skrivanek 2014-01-06 09:10:09 UTC

*** Bug 1047949 has been marked as a duplicate of this bug. ***

Comment 5 errata-xmlrpc 2014-01-21 16:05:30 UTC

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.

http://rhn.redhat.com/errata/RHBA-2014-0040.html