Date: Wed, 5 Mar 2008 15:43:51 -0500 From: Bill Moran <wmoran@potentialtech.com> To: Daniel Feenberg <feenberg@nber.org> Cc: freebsd-questions@freebsd.org Subject: Re: faster booting Message-ID: <20080305154351.fc53a07b.wmoran@potentialtech.com> In-Reply-To: <Pine.GSO.4.64.0803051450540.18940@nber5.nber.org> References: <Pine.GSO.4.64.0803051450540.18940@nber5.nber.org>
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In response to Daniel Feenberg <feenberg@nber.org>: > > We have several network services hosted on a FreeBSD system, and want it > to come up quickly, so that these services (dhcp, nameservice, nis, tftp > etc) are available when systems are restarting after a prolonged power > failure. > > That is, several times a year we have multi-hour power failures (generally > starting at midnight because that is utility maintainance time) and our > UPSs run out of power. That is OK, but we would like the systems to come > up when the power returns, without going to the server room and > restarting systems in a prescribed order. > > In most cases the clients hang because essential services are not > available, and in most cases the clients do not proceed to boot later when > the service does become available. > > 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. -- Bill Moran http://www.potentialtech.com
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