From owner-freebsd-questions Thu Mar 11 2:12:44 1999 Delivered-To: freebsd-questions@freebsd.org Received: from caladan.tdx.co.uk (caladan.tdx.co.uk [195.188.177.4]) by hub.freebsd.org (Postfix) with ESMTP id A1BB815272 for ; Thu, 11 Mar 1999 02:12:02 -0800 (PST) (envelope-from kpielorz@tdx.co.uk) Received: from tdx.co.uk (lorca-tx.tdx.co.uk [195.188.177.242]) by caladan.tdx.co.uk (8.9.3/8.9.3/Kp) with ESMTP id KAA91275; Thu, 11 Mar 1999 10:11:33 GMT Message-ID: <36E796D4.57C2755@tdx.co.uk> Date: Thu, 11 Mar 1999 10:11:32 +0000 From: Karl Pielorz Organization: TDX - The Digital eXchange X-Mailer: Mozilla 4.5 [en] (WinNT; I) X-Accept-Language: en MIME-Version: 1.0 To: "Mike O'Brien" Cc: freebsd-questions@FreeBSD.ORG Subject: Re: Second try: PLEASE! What are "tagged openings"? References: <199903110241.SAA00361@caern.limax.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Mike O'Brien wrote: > > My new 3.1-RELEASE kernel says, vis-a-vis my "ahc" controller: > > (da0:ahc0:0:0:0): tagged openings now 38 > (da0:ahc0:0:0:0): tagged openings now 37 > (da0:ahc0:0:0:0): tagged openings now 36 > > The numbers count down with each period of high disk activity. > > WHAT THE @#$@$%!%$# DOES THIS MEAN????? It tells you how many commands the drive can handle being stacked in it's onboard 'queue' for processing... The 3.1 SCSI system will try and get you as many 'queued' commands on your drive as it can handle, it them slow backs off until the drive is happy (which is why you can see the numbers counting down). > Do I have a "quirky" drive? WHAT??? No, the drive is fine... You tend to find (as a very rough guide) the better / faster drives support more tagged/queued commands... My ancient SCSI ones here support only 16, my good (even though old) DEC3107's go up to 64 :-) Regards, Karl To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message