File Locking

File locking is at the heart of allowing users to work collaboratively, without overwriting each other or creating multiple file versions. With Panzura, file locking is available globally.

Organization-Wide Productivity with File Locking

Panzura CloudFS is the only global file system with real-time file consistency across all sites. That is, any user opening a file for editing will see the most recent saved changes, regardless of where those changes were made. Our patented file locking process plays a crucial role in this process.

With CloudFS, as soon as a user opens a file in your cloud network, it’s locked for editing. If another user tries to open it, they’re notified that the file is already in use and are given the option to open a read-only copy, or to be notified when the file is available for editing. As a result, the second user cannot accidentally overwrite or change the original file; they can only create a copy of it.

Automatic file locking - Panzura

CloudFS physically decouples data and metadata. This decoupling enables the file system to be highly flexible in referencing which physical blocks are used to construct a file. It also allows every filer in the file system to hold a complete copy of the metadata for the whole file system, without having to hold the files themselves.

Panzura’s Global File Locking Follows 3 Simple Principles

Panzura file locking for powerful productivity

ONE When a file is created, the filer on which it was created is designated the Origin, and this is recorded in its metadata.

TWO The Origin always knows which filer currently has the lock, regardless of whether the file is currently locked for editing.

THREE The filer with the lock is the Data Owner, and this information is held in the file’s metadata.

The Data Owner state is transported via metadata snapshots. A filer wanting to assume Data Ownership for a file checks its metadata for the filer on which the file was created (the Origin) and then communicates directly with the Origin, to request the lock and become the Authoritative Write Filer.

If the lock is sitting with the Origin, it will either approve the request, or deny it if the file is open for editing. If the Origin does not currently hold the lock, it tells the requesting filer which location to request it from.

Data Ownership requests and
transitions are frequent events and are negotiated in real time via small peer-to-peer communications among filers.

Panzura file locking for powerful productivity

If the lock is sitting with the Origin, it will either approve the request, or deny it if the file is open for editing. If the Origin does not currently hold the lock, it tells the requesting filer which location to request it from.

Data Ownership requests and transitions are frequent events and are negotiated in real time via small peer-to-peer communications among filers.

Achieving Immediate File Consistency

The final step after a Data Owner transition is to ensure the user now opening the file sees any changes that have been made to the file since the last sync to the object store. This involves a direct peer-to-peer communication between the Origin and the new Data Owner, and possibly the current Data Owner (which might not be the Origin).

Within this peer-to-peer stream, the ownership metadata computes a final delta list of real-time changes that may have occurred since the Data Owner changed. This list, which can be as small as a single file system block, is streamed directly to the new Data Owner via a secure optimized data channel. The new Data Owner processes all remaining deltas, making the file current and consistent.

All file reads and writes from that Panzura system now happen as local I/O operations on the new Data Owner. The Data Owner retains full read/write ownership until a new Data Owner transition occurs.

Byte-Range Locking

Many modern file applications support byte-range locking, to empower even greater productivity. Instead of locking an entire file, byte-range locking only locks the relevant elements of a file that are in use. Multiple users can then collaborate on a single file, at the same time, without overwriting each other’s work or having to merge edits later.

Panzura supports byte-range locking in modern enterprise applications such as AutoDesk Revit and AutoCAD files, Tekla Structures, Bentley Microstation, and Microsoft Office.