[one-users] Error when instantiating VM from persistent image

[Jhon Masschelein]

Hi,

it looks like this is the problem:
> Wed Mar 28 10:50:00 2012 [VMM][I]: error: internal error process
> exited while connecting to monitor: qemu-kvm: -drive
> file=/var/lib/one//25/images/disk.2,if=none,id=drive-ide0-0-0,format=raw:
> could not open disk image /var/lib/one//25/images/disk.2: Permission
> denied

At this point it would appear that oneadmin has access to the disk image 
file /var/lib/one//25/images/disk.2, but qemu does not. The error is 
coming from qemu.


As far as I know, the difference between a persistent image and a non 
persistent image is that, when it is not persistent, the image get 
copied by oneadmin and new permissions are set on the new file, but when 
you are using a persistent image, a symbolic link is created.

With symbolic links, the permissions of the link are not important, the 
permissions on the original file are used.

So, when you look at the file that is listed as the "SOURCE" of your 
image. (Should be something like
/var/lib/one/images/c0dc71ebe6562d4e8c9e186b249bff13,
what are the permissions and is qemu (on the execution node) able to 
read&write to it?

Probably that is the problem and the next thing to look for is why his 
file is not readable by qemu. The file was created by oneadmin at the 
time the onimage command was run on the opennebula server to create the 
Image object.

Now the qemu process on the execution node is trying, and failing, to 
access the file.

Do you have special directory permissions on the image directory? Is it 
an NFS mount that is doing "strange" things?

A couple of other things that could be related:
- did you set dynamic_ownership = 0 in the qemu.conf file onthe 
execution node?
- did you change the user or group the qemu process is running as?

I hope this is of some help to you,

Wkr,

Jhon


-- 
Jhon Masschelein
Senior Systeemprogrammeur
SARA - HPCV

Science Park 140
1098 XG Amsterdam
T +31 (0)20 592 8099
F +31 (0)20 668 3167
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E jhon.masschelein at sara.nl
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