ZFS performance issues (solved?!)

John Birrell jb at what-creek.com
Mon Sep 1 02:15:29 UTC 2008

For those people experiencing a performance degradation since the DTrace import,
please update your copy of src/sys/cddl/compat/opensolaris/kern/opensolaris_kmem.c
by either cvsup of direct edit to remove "#define KMEM_DEBUG".

You only need to rebuild the opensolaris kernel module after this change. The code
is shared between ZFS and DTrace via the opensolaris kernel module.

This is also the reason why you found it necessary to add KDB, DDB and STACK to
your kernel. After removing KMEM_DEBUG, you won't need those.

Please confirm that this solves the problem you have been seeing.

John Birrell

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