雜錄與收藏

• Although simplyfied, UNMAP is still a manual process you have to trigger on the command line. It is still not an inline feature!
• it puts very high load on your storage subsystem so really think twice before reclaiming space (probably this feature should currently ONLY be used during maintenance windows)
• space reclaiming, of course, only makes sense if you delete whole VMs/virtual disks on a datastore. It won't work for files deleted inside the guest OSes
• always consider moving VMs with SVMotion to other datastores and completely delete the empty datastores as an alternative. This will achieve the same result regarding space reclamation but probably with less impact on storage performance

http://www.boche.net/blog/index.php/2013/09/13/vsphere-5-5-unmap-deep-dive/

http://www.v-strange.de/index.php/datacore/12-sansymphony-v/178-vsphere-datacore-unmap-reclaiming-unused-space-from-thin-provisioned-disks