702411 – libvirt fails to save VM into NFS - "Unknown error 255"

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Bug 702411 - libvirt fails to save VM into NFS - "Unknown error 255"

Summary: libvirt fails to save VM into NFS - "Unknown error 255"

Keywords:
Status:	CLOSED ERRATA
Alias:	None
Product:	Red Hat Enterprise Linux 6
Classification:	Red Hat
Component:	libvirt
Sub Component:
Version:	6.1
Hardware:	Unspecified
OS:	Unspecified
Priority:	unspecified
Severity:	high
Target Milestone:	rc
Target Release:	---
Assignee:	Jiri Denemark
QA Contact:	Virtualization Bugs
Docs Contact:
URL:
Whiteboard:	storage
Depends On:
Blocks:	565939 707257
TreeView+	depends on / blocked

Reported:	2011-05-05 15:27 UTC by Rami Vaknin
Modified:	2014-01-12 23:52 UTC (History)
CC List:	10 users (show)
Fixed In Version:	libvirt-0.9.1-1.el6
Doc Type:	Bug Fix
Doc Text:
Clone Of:
Clones:	707257 (view as bug list)
Environment:
Last Closed:	2011-12-06 11:06:38 UTC
Target Upstream Version:
Embargoed:

Attachments	(Terms of Use)
Libvirt and vdsm logs (1.97 MB, application/x-gzip) 2011-05-05 15:27 UTC, Rami Vaknin	no flags	Details
VDSM and Libvirt logs (libvirt-0.9.1-1.el6.x86_64) (827.42 KB, application/x-gzip) 2011-05-31 11:38 UTC, Rami Vaknin	no flags	Details
View All

Links
System	ID	Private	Priority	Status	Summary	Last Updated
Red Hat Product Errata	RHBA-2011:1513	0	normal	SHIPPED_LIVE	libvirt bug fix and enhancement update	2011-12-06 01:23:30 UTC

Description Rami Vaknin 2011-05-05 15:27:16 UTC

Created attachment 497131 [details]
Libvirt and vdsm logs

Environment:
RHEVM 2.3 on dev env, frontend on Windows, backend on RHEL6.
vdsm-4.9-64.el6.x86_64
libvirt-0.8.7-18.el6.x86_64


I suspended VM via RHEVM while working with NFS data storage domain and it became Paused, VDSM logs shows that libvirt failed to save the VM:


Thread-3853::ERROR::2011-05-05 17:30:58,631::vm::456::vm.Vm::(run) vmId=`a5043673-bdef-4111-a12d-9c8afe030d8d`::Traceback (most recent call last):
  File "/usr/share/vdsm/vm.py", line 447, in run
    self._startUnderlyingMigration()
  File "/usr/share/vdsm/libvirtvm.py", line 221, in _startUnderlyingMigration
    self._vm._dom.save(fname)
  File "/usr/share/vdsm/libvirtvm.py", line 267, in f
    ret = attr(*args, **kwargs)
  File "/usr/share/vdsm/libvirtconnection.py", line 59, in wrapper
    ret = f(*args, **kwargs)
  File "/usr/lib64/python2.6/site-packages/libvirt.py", line 619, in save
    if ret == -1: raise libvirtError ('virDomainSave() failed', dom=self)
libvirtError: Error from child process creating '/rhev/data-center/7cb57d18-fd9f-4af2-ae97-c5f0d3d7dff1/5101e0d1-2ec7-4547-9996-af01a3b06370/images/e7a1aa3e-25a0-4c2d-9708-0062d
749a422/05f75dbe-ff32-4e0d-987a-eeed0dd52922': Unknown error 255


I ran "virsh save vm_id destination_file_in_nfs_storage" in order to suspend it to a manually mounted NFS (NFS with the right owner permissions and without SELinux), and I got the following error message:

error: Failed to save domain 6 to /mnt/nfs/6.img
error: Error from child process creating '/mnt/nfs/6.img': Unknown error 243

Note that doing the same to the host's local file system works well.

Comment 2 Jiri Denemark 2011-05-24 14:12:12 UTC

There are two issues here.

The first one is "Unknown error 255" which is caused by child process exiting with -errno instead of just errno. And that issue was fixed upstream by v0.8.8-88-gd152f64:

commit d152f647606a86992b775c4241ba09dce47fd063
Author: Eric Blake <eblake>
Date:   Wed Mar 2 16:25:57 2011 -0700

    util: correct retry path in virFileOperation
    
    In virFileOperation, the parent does a fallback to a non-fork
    attempt if it detects that the child returned EACCES.  However,
    the child was calling _exit(-EACCES), which does _not_ appear
    as EACCES in the parent.
    
    * src/util/util.c (virFileOperation): Correctly pass EACCES from
    child to parent.

The second one (there should be no error) will be tracked by a cloned bz.

Comment 4 Rami Vaknin 2011-05-31 11:36:34 UTC

Retested on libvirt-0.9.1-1.el6.x86_64, the same operation still fails, the logs show a bit different error:

libvirt
-------

14:15:59.450: 12145: error : virFileOpenAsNoFork:1393 : failed to create file '/rhev/data-center/bae5022e-cc52-4de4-b36c-9102d4e3e585/de89a90c-3a88-497d-8652-b50a45504dc6/images
/16bdce8a-9a2d-4a7e-a43a-19b98fb39aef/6762e11d-f972-485d-a25b-de6e9ff90c1f': Permission denied
14:15:59.450: 12145: debug : virStorageFileIsSharedFSType:953 : Check if path /rhev/data-center/bae5022e-cc52-4de4-b36c-9102d4e3e585/de89a90c-3a88-497d-8652-b50a45504dc6/images/
16bdce8a-9a2d-4a7e-a43a-19b98fb39aef/6762e11d-f972-485d-a25b-de6e9ff90c1f with FS magic 26985 is shared
14:15:59.455: 12145: error : virFileOpenAsNoFork:1393 : failed to create file '/rhev/data-center/bae5022e-cc52-4de4-b36c-9102d4e3e585/de89a90c-3a88-497d-8652-b50a45504dc6/images
/16bdce8a-9a2d-4a7e-a43a-19b98fb39aef/6762e11d-f972-485d-a25b-de6e9ff90c1f': Permission denied
14:15:59.455: 12145: error : qemudDomainSaveFlag:2027 : Error from child process creating '/rhev/data-center/bae5022e-cc52-4de4-b36c-9102d4e3e585/de89a90c-3a88-497d-8652-b50a455
04dc6/images/16bdce8a-9a2d-4a7e-a43a-19b98fb39aef/6762e11d-f972-485d-a25b-de6e9ff90c1f': Permission denied


VDSM
----

Thread-6733::INFO::2011-05-31 14:15:59,468::dispatcher::100::Storage.Dispatcher.Protect::(run) Run and protect: teardownVolume, Return response: {'status': {'message': 'OK', 'co
de': 0}}
Thread-6733::DEBUG::2011-05-31 14:15:59,469::utils::330::vm.Vm::(cont) vmId=`1c383153-861f-4765-b8e4-dfb5c403ade7`::Resume statistics collection
Thread-6733::ERROR::2011-05-31 14:15:59,469::vm::165::vm.Vm::(_recover) vmId=`1c383153-861f-4765-b8e4-dfb5c403ade7`::Error from child process creating '/rhev/data-center/bae5022
e-cc52-4de4-b36c-9102d4e3e585/de89a90c-3a88-497d-8652-b50a45504dc6/images/16bdce8a-9a2d-4a7e-a43a-19b98fb39aef/6762e11d-f972-485d-a25b-de6e9ff90c1f': Permission denied
Thread-6733::ERROR::2011-05-31 14:15:59,470::vm::657::vm.Vm::(cont) vmId=`1c383153-861f-4765-b8e4-dfb5c403ade7`::cannot cont while Saving State
Thread-6733::ERROR::2011-05-31 14:15:59,475::vm::220::vm.Vm::(run) vmId=`1c383153-861f-4765-b8e4-dfb5c403ade7`::Traceback (most recent call last):
  File "/usr/share/vdsm/vm.py", line 212, in run
    self._startUnderlyingMigration()
  File "/usr/share/vdsm/libvirtvm.py", line 245, in _startUnderlyingMigration
    self._vm._dom.save(fname)
  File "/usr/share/vdsm/libvirtvm.py", line 295, in f
    ret = attr(*args, **kwargs)
  File "/usr/share/vdsm/libvirtconnection.py", line 59, in wrapper
    ret = f(*args, **kwargs)
  File "/usr/lib64/python2.6/site-packages/libvirt.py", line 664, in save
    if ret == -1: raise libvirtError ('virDomainSave() failed', dom=self)
libvirtError: Error from child process creating '/rhev/data-center/bae5022e-cc52-4de4-b36c-9102d4e3e585/de89a90c-3a88-497d-8652-b50a45504dc6/images/16bdce8a-9a2d-4a7e-a43a-19b98
fb39aef/6762e11d-f972-485d-a25b-de6e9ff90c1f': Permission denied

Comment 5 Rami Vaknin 2011-05-31 11:38:26 UTC

Created attachment 501977 [details]
VDSM and Libvirt logs (libvirt-0.9.1-1.el6.x86_64)

Comment 7 Jiri Denemark 2011-05-31 11:42:50 UTC

That's expected. I left this bz to track the "Unknown error 255" while opened new bug 707257 for the fact that there shouldn't be any error at all.

Your testing confirms that the "Unknown error 255" issue was fixed since you got correct error message saying "Permission denied".

The error will completely disappear after bug 707257 gets fixed by rebasing libvirt to 0.9.2.

Comment 10 Dan Kenigsberg 2011-06-28 19:32:49 UTC

Oded, please specify the libvirt version where this showed up again.

Comment 11 Oded Ramraz 2011-06-29 07:22:06 UTC

I don't see the "Unknown error 255" anymore but i get "Permission denied" error instead 

Thread-3299::ERROR::2011-06-29 09:43:58,993::vm::660::vm.Vm::(cont) vmId=`449cebe4-798d-4b28-8a68-c8f67da9657b`::cannot cont while Saving State
Thread-3299::ERROR::2011-06-29 09:43:58,996::vm::230::vm.Vm::(run) vmId=`449cebe4-798d-4b28-8a68-c8f67da9657b`::Traceback (most recent call last):
  File "/usr/share/vdsm/vm.py", line 222, in run
    self._startUnderlyingMigration()
  File "/usr/share/vdsm/libvirtvm.py", line 251, in _startUnderlyingMigration
    self._vm._dom.save(fname)
  File "/usr/share/vdsm/libvirtvm.py", line 301, in f
    ret = attr(*args, **kwargs)
  File "/usr/share/vdsm/libvirtconnection.py", line 59, in wrapper
    ret = f(*args, **kwargs)
  File "/usr/lib64/python2.6/site-packages/libvirt.py", line 793, in save
    if ret == -1: raise libvirtError ('virDomainSave() failed', dom=self)
libvirtError: Error from child process creating '/rhev/data-center/da1614e0-56c6-46dc-b07e-10698c999d99/9ce60e28-448d-4fa5-8733-1a15d400e295/images/c49cfcf2-743b-4d29-a45b-3a1cf767cc26/c2160041-aa77-4b46-8cb1-e1ff07856fe5': Permission denied

[root@blue-vdsb ~]# rpm -q libvirt                                                                                                                                                                                                           
libvirt-0.9.2-1.el6.x86_64

Comment 12 Jiri Denemark 2011-07-01 11:49:03 UTC

Good, you do see "Permission denied" instead of "Unknown error", which is all this BZ is about and it is fixed. The thing that you shouldn't see any error at all is covered by a separate bug 707257.

Comment 14 Nan Zhang 2011-07-07 05:17:21 UTC

According to comment 11, move it to VERIFIED.

Comment 15 errata-xmlrpc 2011-12-06 11:06:38 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-2011-1513.html

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