From owner-freebsd-stable@freebsd.org Thu Feb 16 21:54:47 2017 Return-Path: Delivered-To: freebsd-stable@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id DFB71CE218B for ; Thu, 16 Feb 2017 21:54:47 +0000 (UTC) (envelope-from dustinwenz@ebureau.com) Received: from internet06.ebureau.com (internet06.ebureau.com [65.127.24.25]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "internet06.ebureau.com", Issuer "internet06.ebureau.com" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id B2BC11B23 for ; Thu, 16 Feb 2017 21:54:47 +0000 (UTC) (envelope-from dustinwenz@ebureau.com) Received: from localhost (localhost [127.0.0.1]) by internet06.ebureau.com (Postfix) with ESMTP id 44E6F7023A6F for ; Thu, 16 Feb 2017 15:47:02 -0600 (CST) X-Virus-Scanned: amavisd-new at mydomain = ebureau.com Received: from internet06.ebureau.com ([127.0.0.1]) by localhost (internet06.ebureau.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ru9T8m479U8k for ; Thu, 16 Feb 2017 15:47:01 -0600 (CST) Received: from square.office.ebureau.com (unknown [10.10.20.22]) by internet06.ebureau.com (Postfix) with ESMTPSA id D91097023A65 for ; Thu, 16 Feb 2017 15:47:01 -0600 (CST) From: Dustin Wenz Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (Mac OS X Mail 10.2 \(3259\)) Subject: Jailed periodic daily scripts smashing CPU Message-Id: <321260F8-95D8-4C21-90B5-FDB0F6FF98F9@ebureau.com> Date: Thu, 16 Feb 2017 15:47:01 -0600 To: freebsd-stable@freebsd.org X-Mailer: Apple Mail (2.3259) X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 16 Feb 2017 21:54:48 -0000 I have a number of servers with roughly 60 jails running on each of = them. On these hosts, I've had to disable the periodic security scans = due to overly high disk load when they run (which is redundant in jails = anyway). However, I still have an issue at 3:01am where the CPU is = consumed by dozens of 'xz -c' processes. This is apparently daily log = rolling, which I can't exactly disable. The effect is that our processing applications experience a major = slowdown for about 15 seconds every morning, which is just enough that = it's starting to get people's attention. What is the best way to mitigate this? I'm aware of the cron jitter = feature, but I'm not sure of the 60-second jitter maximum would be = enough (especially if I wanted to start utilizing more jails). - .Dustin=