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: 4e4d520755 ("xfs: add the zoned space allocator")
Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
This commit is contained in:
Hans Holmberg 2025-04-09 12:39:56 +00:00 committed by Carlos Maiolino
parent c6f1401b1d
commit c7b67ddc3c

View File

@ -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/