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Why all disk space in my ceph cluster seems assigned to a VM?

asked 2014-07-11 14:45:49 -0500

Nicolas Zin gravatar image

updated 2014-07-11 16:33:54 -0500

smaffulli gravatar image

I have a RDO openstack installation with Ceph as backend. I have flavor configured with normal disk + ephemeral. let take my m1.tiny flavor: 4G of disk + 4G ephemeral.

When I boot a VM, and do a fdisk: /dev/vda is 4TB: the size of the free remaining ceph cluster (or something like this) /dev/vdb is 4G, the normal size of the ephemeral disk.

I don't understand why I see the size of the ceph cluster (~4T) for /dev/vda and not the allocated size (4G).

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Does creating a disk directly with cinder present the same way? Or is this only when launching an instance with a flavor?

SamYaple gravatar imageSamYaple ( 2014-07-14 12:59:30 -0500 )edit

No: when i create a volume of 2G, it appears as 2G.

Note: in nova when I do a "nova flavor-show m1.small", I see the correct size, but without unit. I wonder where is defined the unit (GB, TB...) if any.

Nicolas Zin gravatar imageNicolas Zin ( 2014-07-14 15:15:51 -0500 )edit

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answered 2014-07-14 11:14:42 -0500

Nicolas Zin gravatar image

Indeed the problem seems to be elsewhere: my flavor is 4G, but openstack try to create a disk of 4000 G. there is disk size conversion problem. Same with a disk of 20G => it tries to create 20TB (and is limited by the underlying storage) weird

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Asked: 2014-07-11 14:45:49 -0500

Seen: 459 times

Last updated: Jul 14 '14