What is a PIT file in Data ONTAP?
- ONTAP 9
- Clustered Data ONTAP 8.3
- Data ONTAP 7-mode
- Any NAS or SAN protocol
- A Point-In-Time (PIT) file is a special file used for ODX or Copy Offload procedures.
- This is also called VAAI Storage Acceleration in ESX.
- Copy Offload is the process of sending only control data from the client to ONTAP while copying from one folder to another on the same storage node.
- The contents of the file are transferred internally in ONTAP and the client requests the blocks to be transferred.
- This is used instead of sending the whole file over the network.
- This can speed up performance compared to the network, particularly in high client or network load situations
- The PIT file is the container which ONTAP uses to copy the blocks internally from one folder to another
- TR-4191 page 11 and 21 discuss further about the PIT file
- ONTAP may delete the PIT file in rare situations, such as a SnapMirror break. When this happens, an EMS message will be logged similar to this:
Thu Sep 24 03:07:09 -0600 [node1: token_mgr_admin: token.pit.file.deleted:notice]: PIT file in volume vol1 was deleted.