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Subject: Re: ZFS stalled after some mirror disks were lost
From: Andriy Gapon <avg@FreeBSD.org>
To: Ben RUBSON <ben.rubson@gmail.com>, Freebsd fs <freebsd-fs@FreeBSD.org>
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On 02/10/2017 23:55, Andriy Gapon wrote:
> Maybe that caused a domino effect in ZFS code.  I see a lot of threads waiting
> either for spa_namespace_lock or a spa config lock (a highly specialized ZFS
> lock).  But it is hard to untangle their inter-dependencies.

Forgot to add.  It would be nice to determine an owner of spa_namespace_lock.
If you have debug symbols then it can be easily done in kgdb on the live system:
(kgdb) p spa_namespace_lock

-- 
Andriy Gapon