From owner-freebsd-scsi@FreeBSD.ORG Mon Apr 5 06:37:29 2010 Return-Path: Delivered-To: freebsd-scsi@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E0EBC106566B for ; Mon, 5 Apr 2010 06:37:29 +0000 (UTC) (envelope-from mavbsd@gmail.com) Received: from fg-out-1718.google.com (fg-out-1718.google.com [72.14.220.157]) by mx1.freebsd.org (Postfix) with ESMTP id 6F28A8FC14 for ; Mon, 5 Apr 2010 06:37:29 +0000 (UTC) Received: by fg-out-1718.google.com with SMTP id d23so1006921fga.13 for ; Sun, 04 Apr 2010 23:37:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:sender:message-id:date:from :user-agent:mime-version:to:cc:subject:references:in-reply-to :content-type:content-transfer-encoding; bh=Qrr0Ek7fsmKLdcQ5YfDbk7cnJCbo85XKCxGuGeZZuis=; b=cdTYtiYCWQhyi1t7dcmbICusoz+DsG8r5VgDc26qjGfnzQt7dqLQo5Vmu98P07stiN ywySL8FjgCULfaqjdiLJSyzXUeOLkb5FAqwqdczMa3T32yiQx8It+2fy/mXt1ML+wMbG 2kdXWjHETeM1+R9lx7DJXJP2QPJ9ydYlfMYZo= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; b=F+8Ha0upwJwPXbOq0sPGETeLcgx9V6kIyJcguVtbaqVvgxxoIJ9aDhryHRyTM9bNsK U0RraAt2Mu0AgBPVJVIB9ee9qTBZf6vTyBMoUp1EtEuOnwtjCOaX0AmmF8YpufHtwdBz D5NmnBJV/FW+1q0LX7yD5NGzSNOOZXVwawcbk= Received: by 10.87.73.1 with SMTP id a1mr8378630fgl.17.1270449448342; Sun, 04 Apr 2010 23:37:28 -0700 (PDT) Received: from mavbook.mavhome.dp.ua (pc.mavhome.dp.ua [212.86.226.226]) by mx.google.com with ESMTPS id 16sm7799263fxm.4.2010.04.04.23.37.27 (version=SSLv3 cipher=RC4-MD5); Sun, 04 Apr 2010 23:37:27 -0700 (PDT) Sender: Alexander Motin Message-ID: <4BB98522.6000704@FreeBSD.org> Date: Mon, 05 Apr 2010 09:37:22 +0300 From: Alexander Motin User-Agent: Thunderbird 2.0.0.24 (X11/20100402) MIME-Version: 1.0 To: mj@feral.com References: <1269900407.00235175.1269888603@10.7.7.3> In-Reply-To: <1269900407.00235175.1269888603@10.7.7.3> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: freebsd-scsi@freebsd.org Subject: Re: adding a "retry command after a delay" error X-BeenThere: freebsd-scsi@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SCSI subsystem List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 05 Apr 2010 06:37:30 -0000 Matthew Jacob wrote: > This is something I whipped up for dealing with some > active/active-after-failover-time systems. I wanted to have a general > facility to say of an ASC/ASCQ- retry the command, but after a period of > delay. > > Wonder if anyone had comments? > http://people.freebsd.org/~mjacob/delay_diffs.txt I am not SCSI expert yet, but it seems OK for me. But I see two related questions there: delay time and number of retries allowed. Most of peripheral drivers now AFAIR ask to do only few (2-5) retries, so if delay will be short - it may give up too early, but long delay will probably reduce performance. -- Alexander Motin