From owner-freebsd-questions Thu May 6 0:34:56 1999 Delivered-To: freebsd-questions@freebsd.org Received: from allegro.lemis.com (allegro.lemis.com [192.109.197.134]) by hub.freebsd.org (Postfix) with ESMTP id AB51814DDB for ; Thu, 6 May 1999 00:34:49 -0700 (PDT) (envelope-from grog@freebie.lemis.com) Received: from freebie.lemis.com (freebie.lemis.com [192.109.197.137]) by allegro.lemis.com (8.9.1/8.9.0) with ESMTP id RAA22540; Thu, 6 May 1999 17:04:48 +0930 (CST) Received: (from grog@localhost) by freebie.lemis.com (8.9.3/8.9.0) id RAA81036; Thu, 6 May 1999 17:04:47 +0930 (CST) Date: Thu, 6 May 1999 17:04:46 +0930 From: Greg Lehey To: Mark Ovens Cc: Questions Subject: Re: delays during boot Message-ID: <19990506170446.K40359@freebie.lemis.com> References: <37305116.DCBB1666@castle.net> <19990506085525.J40359@freebie.lemis.com> <373137F5.3DE5DC6A@uk.radan.com> <19990506161419.I40359@freebie.lemis.com> <37314346.4A7CB5D@uk.radan.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.95.4i In-Reply-To: <37314346.4A7CB5D@uk.radan.com>; from Mark Ovens on Thu, May 06, 1999 at 08:22:46AM +0100 WWW-Home-Page: http://www.lemis.com/~grog X-PGP-Fingerprint: 6B 7B C3 8C 61 CD 54 AF 13 24 52 F8 6D A4 95 EF Organization: LEMIS, PO Box 460, Echunga SA 5153, Australia Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-41-739-7062 Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Thursday, 6 May 1999 at 8:22:46 +0100, Mark Ovens wrote: > Greg Lehey wrote: >> >> On Thursday, 6 May 1999 at 7:34:29 +0100, Mark Ovens wrote: >>> Greg Lehey wrote: >>>> >>>> On Thursday, 6 May 1999 at 8:59:31 +1200, Jonathan Chen wrote: >>>>> On Wed, 5 May 1999, gkaplan wrote: >>>>> >>>>>> During the boot process for 2.2.8 there are two significant delays is >>>>>> the startup process. They both seem to relate to disk initialization >>>>>> (ide) the combined time of delay is 30 to 45 second. Is there a >>>>>> modification the I could make to the startup that would shorten this >>>>>> time without causing an undesirable side effect. >>>>> >>>>> You could compile a custom kernel so that it doesn't probe for >>>>> non-existent IDE devices. >>>> >>>> You can also disable them in UserConfig. >>> >>> On a closely related note, what is SCSI_DELAY for? The message says >>> "waiting for SCSI devices to settle" but what exactly is "settling"? I >>> can't set mine any lower than 10 seconds and get successful probes >>> *every* boot. >> >> To quote: >> >> SCSI_DELAY is the number of milliseconds to wait after resetting the >> SCSI bus. This is most evident when probing. This value used to be >> in seconds: be careful when upgrading. >> >> Make sense? > > Yes. I knew that much though (it's in the handbook). What I don't > understand (but would like to) is what exactly are the devices doing > when the "settle", i.e. from a h/w point of view, what happens to the > devices that takes 10 seconds when the SCSI bus is reset? In most cases, they're idle. For some reason, though, some devices (I suspect mainly tapes) take a long while to recover from bus resets, and so the system just waits a while. I have reduced mine to 3 seconds (though I have lots of funny tapes on the system), and it works fine. YMMV. Greg -- When replying to this message, please copy the original recipients. For more information, see http://www.lemis.com/questions.html See complete headers for address, home page and phone numbers finger grog@lemis.com for PGP public key To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message