Date: Wed, 05 Mar 2008 16:44:22 -0600 From: Kevin Kinsey <kdk@daleco.biz> To: Bill Moran <wmoran@potentialtech.com> Cc: Daniel Feenberg <feenberg@nber.org>, freebsd-questions@freebsd.org Subject: Re: faster booting Message-ID: <47CF2246.5050007@daleco.biz> In-Reply-To: <20080305171739.1f51a11a.wmoran@potentialtech.com> References: <Pine.GSO.4.64.0803051450540.18940@nber5.nber.org> <20080305154351.fc53a07b.wmoran@potentialtech.com> <Pine.GSO.4.64.0803051623430.29394@nber5.nber.org> <20080305171739.1f51a11a.wmoran@potentialtech.com>
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Bill Moran wrote: >>>> So, is there advice anywhere about speeding up the boot process? It >>>> appears that most of the 1 minute 45 seconds to boot our system is wait >>>> time for checking the existence of non-existant hardware and would not be >>>> appreciable reduced with a faster CPU or disk. Are there kernel options >>>> that we could use to avoid this checking? Would recompiling the kernel in >>>> some specialized way help? Would pico-bsd be faster? >>>> >>>> About the only thing I can find is to reduce the 10 second boot screen >>>> delay - but we need to cut more than 30 seconds. >>>> >>>> The server is statically configured but the clients obtain network >>>> configuration from dhcp and pxeboot with nfs mounted root directories. >>>> Clients are FreeBSD and Linux, and we are not eager to give up pxeboot as >>>> it has greatly simplified maintainance. >>>> >>>> Any suggestions, pointers much appreciated. >>> Three things I can think of: >>> * The 10 sec boot delay, which you already mentioned >>> * Make sure the wait time for SCSI devices is a low as reliably works. >>> If it only has SCSI disks, this could probably very short, 1 sec or so >>> * Recompile your kernel removing any devices that don't exist in your >>> hardware. >>> >>> I'm not buying this, however. My laptop boots in ~30 seconds with a >>> mostly stock kernel. Please provide specific details as to what's >>> slowing it down. Are you sure it's not a slow BIOS? Many of the Dell >>> systems we have take several minutes with BIOS self-checks before the >>> OS even starts to boot. >> The BIOS time isn't terrible - BTX shows up on the console within 15 >> seconds. The major delays happen when the last console message is about >> atapci: (25 seconds) and ad2: (15 seconds). > > Funky. That's a Looong time to wait for an ATA controller to determine > whether or not their's a disk attached. Do you have an ad2? If not, > you might want to check the BIOS to see if there's an option to disable > that particular part of the ATA chain to see if that speeds FreeBSD's > probe up. Let's be sure of this, though; are we actually talking about an ATA controller issue? The phrase "last console message" doesn't necessarily mean it's the ATA controller, but whatever is *next* in the bootup process, AFAICT, *after* the probe of /dev/ad2, which, on my systems is the mounting of the root filesystem. OTOH, turning off BIOS probes for disks that don't exist is a good idea, IMHO. Kevin Kinsey
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