From owner-freebsd-questions@FreeBSD.ORG Thu Oct 9 22:53:54 2014 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 52E3EC30 for ; Thu, 9 Oct 2014 22:53:54 +0000 (UTC) Received: from mail.magehandbook.com (173-8-4-45-WashingtonDC.hfc.comcastbusiness.net [173.8.4.45]) by mx1.freebsd.org (Postfix) with ESMTP id 28ECF967 for ; Thu, 9 Oct 2014 22:53:53 +0000 (UTC) Received: from [192.168.1.50] (Mac-Pro.magehandbook.com [192.168.1.50]) by mail.magehandbook.com (Postfix) with ESMTP id 3jDSQ81rTqzlt for ; Thu, 9 Oct 2014 18:53:52 -0400 (EDT) Date: Thu, 09 Oct 2014 18:53:52 -0400 From: Daniel Staal Reply-To: FreeBSD Questions To: FreeBSD Questions Subject: Re: Next Steps to Debug ZFS Hang? Message-ID: In-Reply-To: References: <1412732931033.813626ca@Nodemailer> X-Mailer: Mulberry/4.0.8 (Mac OS X) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 09 Oct 2014 22:53:54 -0000 --As of October 8, 2014 9:28:05 PM -0700, Nick Sivo is alleged to have said: >> Not sure if this will be helpful, but at least it shouldn't hurt: When >> was the last time you ran a scrub? Also, how much RAM do you have and >> where is your swap? (The only times I've had permanent hangs from ZFS >> was when I ran out of RAM and was trying to swap to ZFS...) > > The server has 64GB ECC RAM, and no swap at the moment. I've since > rebooted the box, but a scrub today revealed no errors, and there was > nothing in the console or any log files about disk or controller > errors or timeouts. --As for the rest, it is mine. Note that I'm still just going by 'standard checks', but why don't you have any swap? I know you probably wouldn't use it with that much RAM around, but FreeBSD still performs better with it - and it wouldn't surprise me completely if that was causing your issue. (It shouldn't, in an ideal world - but it's an oddity on your system that might be causing issues, if there's an uncovered corner case.) Setting up a small ramdisk for swap - or even putting some small swap-on-zfs - might be worth checking to see if it seems to prevent the issue. (Note that swap-on-zfs has a 'worst case' scenario that crashes the box if you run out of RAM. It's happened to me, and I was able to recover, but it took a while.) Anyway, I'm mostly trying to keep your question alive in hopes that someone who's more knowledgeable can answer it. ;) Daniel T. Staal --------------------------------------------------------------- This email copyright the author. Unless otherwise noted, you are expressly allowed to retransmit, quote, or otherwise use the contents for non-commercial purposes. This copyright will expire 5 years after the author's death, or in 30 years, whichever is longer, unless such a period is in excess of local copyright law. ---------------------------------------------------------------