Commit c7b67ddc authored by Hans Holmberg's avatar Hans Holmberg Committed by Carlos Maiolino
Browse files

xfs: document zoned rt specifics in admin-guide 



Document the lifetime, nolifetime and max_open_zones mount options
added for zoned rt file systems.

Also add documentation describing the max_open_zones sysfs attribute
exposed in /sys/fs/xfs/<dev>/zoned/

Fixes: 4e4d5207 ("xfs: add the zoned space allocator")
Signed-off-by: default avatarHans Holmberg <hans.holmberg@wdc.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Signed-off-by: default avatarCarlos Maiolino <cem@kernel.org>
parent c6f1401b

Documentation/admin-guide/xfs.rst

+29 −0
Original line number Diff line number Diff line
@@ -124,6 +124,14 @@ When mounting an XFS filesystem, the following options are accepted. 
	controls the size of each buffer and so is also relevant to

	this case.



  lifetime (default) or nolifetime

	Enable data placement based on write life time hints provided

	by the user. This turns on co-allocation of data of similar

	life times when statistically favorable to reduce garbage

	collection cost.



	These options are only available for zoned rt file systems.



  logbsize=value

	Set the size of each in-memory log buffer.  The size may be

	specified in bytes, or in kilobytes with a "k" suffix.
@@ -143,6 +151,14 @@ When mounting an XFS filesystem, the following options are accepted. 
	optional, and the log section can be separate from the data

	section or contained within it.



  max_open_zones=value

	Specify the max number of zones to keep open for writing on a

	zoned rt device. Many open zones aids file data separation

	but may impact performance on HDDs.



	If ``max_open_zones`` is not specified, the value is determined

	by the capabilities and the size of the zoned rt device.



  noalign

	Data allocations will not be aligned at stripe unit

	boundaries. This is only relevant to filesystems created
@@ -546,6 +562,19 @@ The interesting knobs for XFS workqueues are as follows: 
Zoned Filesystems

=================



For zoned file systems, the following attribute is exposed in:



  /sys/fs/xfs/<dev>/zoned/



  max_open_zones		(Min:  1  Default:  Varies  Max:  UINTMAX)

	This read-only attribute exposes the maximum number of open zones

	available for data placement. The value is determined at mount time and

	is limited by the capabilities of the backing zoned device, file system

	size and the max_open_zones mount option.



Zoned Filesystems

=================



For zoned file systems, the following attributes are exposed in:



 /sys/fs/xfs/<dev>/zoned/