From owner-freebsd-stable@freebsd.org Fri Feb 17 07:34:44 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 5496ECE2E15 for ; Fri, 17 Feb 2017 07:34:44 +0000 (UTC) (envelope-from Guy.TABRAR@uk.bnpparibas.com) Received: from lonmail9.bnpparibas.com (lonmail9.bnpparibas.com [155.140.133.144]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "lonmail9.bnpparibas.com", Issuer "Symantec Class 3 Secure Server CA - G4" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id D1F9012A3 for ; Fri, 17 Feb 2017 07:34:43 +0000 (UTC) (envelope-from Guy.TABRAR@uk.bnpparibas.com) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=uk.bnpparibas.com; i=@uk.bnpparibas.com; l=1527; q=dns/txt; s=20151010; t=1487316883; x=1518852883; h=from:to:subject:date:message-id:references:in-reply-to: mime-version:content-transfer-encoding; bh=HOl29uvCkFqS1/mU/yJBJvl11SlW5iJre3I53pSV5Io=; b=rOJKwWLkZVlyMu0hpH2x4nlswZC5WhZvh8nNTBEjRMDDKBGtGTXeJtUl knnPFC1UcJgPD3tfvGc9WiDRLvabebbh5oWNDolWrhmUXSBUsHHLlf54i XyV2wXfTZiERp2SdhVqejBbQnHdyvp4UZ9kk3cYlcj+NGrIbBxiO0iSb9 N13/VKO16wSypmcjtr2oSs/si9ltYGAPdIPuX2cBe+4vduOqEI9q1+j1z 290XWMDEtY5wOPvU8EePpDsIqSur4rSlTXnglRL8C6aq9Kj7IwNcBhovd Q0BOeEf4PW6GoJ2QdPA342X9xZW/s8RzxZVXPVLqFBhoZFRGbFj4zE69U A==; X-IronPort-AV: E=Sophos;i="5.35,171,1484006400"; d="scan'208";a="13194838" X-HopCount: * X-IronPort-AV: E=Sophos;i="5.35,171,1484006400"; d="scan'208";a="162536102" From: Guy TABRAR To: Miroslav Lachman <000.fbsd@quip.cz>, Dustin Wenz , "freebsd-stable@freebsd.org" Subject: RE: Jailed periodic daily scripts smashing CPU Thread-Topic: Jailed periodic daily scripts smashing CPU Thread-Index: AQHSiJ9TB9MTlD6pxEuH83YkTHTCp6FsZrcAgABmoEA= Date: Fri, 17 Feb 2017 07:29:32 +0000 Message-ID: <2112385FC012E541A52D6A28563A5572011894C8@LONS00110044.mercury.intra> References: <321260F8-95D8-4C21-90B5-FDB0F6FF98F9@ebureau.com> <58A64FCA.5080302@quip.cz> In-Reply-To: <58A64FCA.5080302@quip.cz> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 X-CFilter-Loop: Reflected Content-Transfer-Encoding: quoted-printable 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: Fri, 17 Feb 2017 07:34:44 -0000 What about: @daily sleep ${RANDOM:0:2}m ; /some/cron/job.sh Which gives you a jitter of up to 99 minutes. Cheers, Guy -----Original Message----- From: owner-freebsd-stable@freebsd.org [mailto:owner-freebsd-stable@freebsd= .org] On Behalf Of Miroslav Lachman Sent: 17 February 2017 01:20 To: Dustin Wenz; freebsd-stable@freebsd.org Subject: Re: Jailed periodic daily scripts smashing CPU Dustin Wenz wrote on 2017/02/16 22:47: > I have a number of servers with roughly 60 jails running on each of = > them. On these hosts 60 is way more than we have on our jailers. Daily / security scripts are ve= ry disk IO intensive so we end up with changing time in /etc/crontab in eac= h jail for periodic tasks. The best way is to randomize these times on jail creation time. Miroslav Lachman _______________________________________________ freebsd-stable@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org" ___________________________________________________________ This e-mail may contain confidential and/or privileged information. If you = are not the intended recipient (or have received this e-mail in error) plea= se notify the sender immediately and delete this e-mail. Any unauthorised c= opying, disclosure or distribution of the material in this e-mail is prohib= ited. Please refer to http://www.bnpparibas.co.uk/en/email-disclaimer/ for additi= onal disclosures.