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Hello,

I've seen that it's possible to add polsters to ceilometer to gather 
additional metrics.
I need to measure storage usage of my users, specially image usage 
(instance snapshots), where we still cannot have quotas.

Does someone have already done something similar, where can I start to 
investigate ?
I've seen some documentation to add Ceph RadosGW usage to Ceilometer, 
but it's not adaptable to my use case.