[Bug 229670] ZFS ARC limit vfs.zfs.arc_max from /boot/loader.conf is not respected

bugzilla-noreply at freebsd.org bugzilla-noreply at freebsd.org
Mon Jul 16 18:20:11 UTC 2018


https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=229670

Josh Paetzel <jpaetzel at FreeBSD.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jpaetzel at FreeBSD.org

--- Comment #6 from Josh Paetzel <jpaetzel at FreeBSD.org> ---
The 1GB per TB rule is a stab at how much RAM is needed to cache the working
set and deliver RAM like read performance.

It's not really intended to indicate how much RAM you need to operate a pool. 
(I've imported and used 1PB pools on heads with 32GB of RAM before)

The only real linear limit I know of is datasets/zvols consume ~ 1MB/RAM each.


So a system with 4000 datasets would need ~ 4GB RAM just for the dataset
metadata.

-- 
You are receiving this mail because:
You are the assignee for the bug.


More information about the freebsd-bugs mailing list