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Launch VM (Compute/XenServer): Error: Could not stat device /dev/sda - No such file or directory.

asked 2011-01-31 19:11:55 -0600

juanperez gravatar image


When trying to boot vm, Status shows as 'active', but vm never boots up in XenServer, but the vm's glance disk does show up in XenServer.

(when run: cloudservers boot test --flavor=1 --image=11) (when run: cloudservers list)

Logs pasted @

I tried different images, none of them Maverick, but they both had the same error.

It looks like this may be related to Bug ( ( ), but the fix was merged in 602, and I'm running revision 631.

Thank you.

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answered 2011-02-02 01:34:33 -0600

salvatore-orlando gravatar image

Thanks for the update Juan.

Changing the flag to false makes sense in order to obtain the rigth prefix for devices. I think your last problem might be related to access rigths on your compute node. It seems the user which is running nova services cannot open the device for writing (the failure occurs when partitioning the VDI mounted in /dev/xvda).

One way to fix this is to update udev rules. This rule should be added to /etc/udev/rules.d/50-udev.rules (default udev rules file, actual file might differ on your machine)

KERNEL=="xvd[a-z]", GROUP="$youruser", MODE="0660"

Hope this helps, Salvatore

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answered 2011-02-01 10:53:21 -0600

salvatore-orlando gravatar image

Hi Juan,

Looking at the log you pasted, it seems the problem might be the same as bug #705790. For a better assessment, It would be very helpful to know a few more details: 1) are you running the compute node on a maverick distro? 2) is the compute node running on a VM? If yes, is this VM running on the same hypervisor on which you want to launch the instance? 3) which log level are you currently launching nova with?

Thanks, Salvatore

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answered 2011-02-01 15:17:18 -0600

juanperez gravatar image

Hi Salvatore,

1) I"m using Lucid 10.04 on compute node 2) Yes, compute node is running on a VM on the same hypervisor on which i'm trying to launch an instance. 3) Logging appears to be full

Update, I was able to get past the error by changing the "--xenapi_remap_vbd_dev" entry in the nova.conf file to false from true:


But, I'm now seeing a similar error saying that permission denied to "/dev/xvda":

(nova.compute.manager): TRACE: Command: parted --script /dev/xvda mklabel msdos (nova.compute.manager): TRACE: Exit code: 1 (nova.compute.manager): TRACE: Stdout: 'Error: Error opening /dev/xvda: Permission denied\n'

Thank you.

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Asked: 2011-01-31 19:11:55 -0600

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Last updated: Feb 02 '11