I have a v series 3210 and two sql servers that have 3.91TB presented to each server. They are seup as follows
windows 2008, sql2008 and the sql is configured for sql mirroring for failover. The size of the database is 2.2TB I have snap manager for sql running on one server and it does two snap shots per day and deletes any older than two days.
within windows i view the drive on one server and the sql drive shows a total size of 2.92TB and free sapce of 363gb
on the mirored server the total size is 2.92TB and the free size is over 900gb.
within OnCommand the when i view the volumes it shows as 67% used when infact if you go by what windows shows as free space its more around the 88% mark. The available space is 1.3TB within OnCommand
when i then look at the luns its shows 87% used and the second server and 69% used.
Both drives presented to each server are from the same aggregate and thin provisioning is enabled. I am confused as the only data on the two servers is the database at 2.2TB that is mirrored. Snap shot output below which shows its not related to that.
Once block is allocated to a LUN, it remains allocated on NetApp even if operating system later marks it as "free". So one host at some point had 2.6TB of data on a file system on the LUN. That now excess data are deleted in file system does not make blocks that once contained deleted data available for NetApp.
If you are using SnapDrive, you could try space reclamation to return free space on file system to NetApp free space pool.