Currently the thin volume feature does not support UNMAP, thus the space can’t be reclaimed for use by other volumes. Thin volumes are positioned for data sets that grow slowly over time and can thus benefit from the economics of under-provisioning.
In the next release (SANtricity 11.25), SCSI UNMAP commands issued by a host will be supported. This allows for the deleted space to be reclaimed for use by other volumes within the dynamic disk pool.
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