Bug 269503 - docs.freebsd.org: default vfs.zfs.arc.meta_limit
Summary: docs.freebsd.org: default vfs.zfs.arc.meta_limit
Status: Open
Alias: None
Product: Documentation
Classification: Unclassified
Component: Books & Articles (show other bugs)
Version: Latest
Hardware: Any Any
: --- Affects Some People
Assignee: freebsd-doc (Nobody)
URL:
Keywords: needs-patch, needs-qa
Depends on:
Blocks: 261212
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Reported: 2023-02-11 22:37 UTC by Christos Chatzaras
Modified: 2023-11-27 20:16 UTC (History)
3 users (show)

See Also:
grahamperrin: maintainer-feedback? (fs)

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Description Christos Chatzaras 2023-02-11 22:37:52 UTC 
https://docs.freebsd.org/en/books/handbook/zfs/#zfs-advanced writes that vfs.zfs.arc.meta_limit is 1/4 of vfs.zfs.arc.max but it's (3/4 or 75%).

Reference: https://forums.freebsd.org/threads/zfs-arc-metadata.88015
Comment 1 Graham Perrin freebsd_committer freebsd_triage 2023-02-12 13:15:45 UTC 
I don't know about ZFS in 12.4-RELEASE. 

----

For OpenZFS in 13.0-RELEASE and greater, take care to not confuse these two: 

vfs.zfs.arc.meta_limit_percent: 75
vfs.zfs.arc.meta_limit: 0

fs@ please, can you advise? 


References: 

<https://openzfs.github.io/openzfs-docs/Performance%20and%20Tuning/Module%20Parameters.html#zfs-arc-meta-limit>

<https://openzfs.github.io/openzfs-docs/Performance%20and%20Tuning/Module%20Parameters.html#zfs-arc-meta-limit-percent>

----

From <https://openzfs.github.io/openzfs-docs/Developer%20Resources/OpenZFS%20Exceptions.html?highlight=6914>: 

> 6914    •    Under Linux the arc_meta_limit can be tuned with the 
> zfs_arc_meta_limit_percent module option.

Is Linux still exceptional?
Comment 2 Minsoo Choo 2023-11-26 14:15:37 UTC 
This report should be in Documentation->Books&Articles