i am been phased with a sensitive issue. apparently i have a netapp filer who presents storage to a mailbox server with storage space LUN of over 20GB. now for some reasons i don't know, that space in that mailbox server has gone "missing" now showing 0GB. my management wants me to initiate a process that will surely get that space back through either doing a restore from the netapp box or any other method applicable. i was thinking of doing a snaprestore of the volume that the LUN contains and using a "snapshot" that existed days before when this issue was non-existent. someone suggested i "Clone" the target LUN first and then "Split" it before doing a snaprestore. so my question goes thus:
1. is it best practice to clone the LUN and split it before initiating a snaprestore?
2. is there any other method out there existing that can help me get that missing space without me doing a snaprestore?
3. are there any implications of using the snaprestore technology to achieve this?
4. can this issue be server related because the storage space on the volume still reads intact when i do a 'df -h" ?
please any suggestions on how i can achieve this will be most appreciated. thanks in advance