Write Anywhere File Layout

WAFL
Developer(s)NetApp
Full nameWrite Anywhere File Layout
Limits
Max volume sizeup to 100 TB (limited by containing aggregate size; variable maximum depending on platform; limited to 16TB when using Deduplication{ONTAP 8.2 now supports dedup to max volume size supported on platform})
Max file sizeup to 16 TB[1]
Features
Dates recordedatime, ctime, mtime
File system
permissions
UNIX permissions and ACLs
Transparent
compression
Yes (Ontap 8.0 onwards)
Transparent
encryption
Yes (since Ontap 9.1;[2] possible with 3rd party appliances like Decru DataFort for older versions)
Data deduplicationYes (FAS Dedup: periodic online scans, block based;)
Copy-on-writeYes
Other
Supported
operating systems
ONTAP

The Write Anywhere File Layout (WAFL) is a proprietary file system that supports large, high-performance RAID arrays, quick restarts without lengthy consistency checks in the event of a crash or power failure, and growing the filesystems size quickly. It was designed by NetApp for use in its storage appliances like NetApp FAS, AFF, Cloud Volumes ONTAP and ONTAP Select.

Its author claims that WAFL is not a file system, although it includes one.[3] It tracks changes similarly to journaling file systems as logs (known as NVLOGs) in dedicated memory storage device non-volatile random access memory, referred to as NVRAM or NVMEM. WAFL provides mechanisms that enable a variety of file systems and technologies that want to access disk blocks.

  1. ^ "Storage limits". library.netapp.com.
  2. ^ "NetApp Volume Encryption, The Nitty Gritty | IOPS.ca". 30 November 2016.
  3. ^ "Is WAFL a File System?". Blogs.netapp.com. Archived from the original on July 15, 2014.