Editing GFS2 (section)

== Features of GFS2 compared with GFS ==

GFS2 adds a number of new features which are not in GFS. Here is a summary of those features not already mentioned in the boxes to the right of this page:

* The metadata filesystem (really a different root) – see [[#Compatibility and the GFS2 meta filesystem|Compatibility and the GFS2 meta filesystem]] below
* GFS2 specific trace points have been available since kernel 2.6.32
* The XFS-style quota interface has been available in GFS2 since kernel 2.6.33
* Caching ACLs have been available in GFS2 since 2.6.33
* GFS2 supports the generation of "discard" requests for thin provisioning/SCSI TRIM requests
* GFS2 supports I/O barriers (on by default, assuming underlying device supports it. Configurable from kernel 2.6.33 and up)
* FIEMAP ioctl (to query mappings of inodes on disk)
* [[Splice (system call)]] support
* mmap/splice support for journaled files (enabled by using the same on disk format as for regular files)
* Far fewer tunables (making set-up less complicated)
* Ordered write mode (as per ext3, GFS only has writeback mode)