Date: Sat, 31 Jan 2004 08:47:38 -0800 (PST) From: Julian Elischer <julian@elischer.org> To: Bjorn Eikeland <bjorn@eikeland.info> Cc: cpghost@cordula.ws Subject: Re: Transferring the root filesystem to a ramdisk? Message-ID: <Pine.BSF.4.21.0401310845250.38031-100000@InterJet.elischer.org> In-Reply-To: <opr2m868m9omdbx5@localhost>
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On Sat, 31 Jan 2004, Bjorn Eikeland wrote: > I'm probably in over my head here, but; > chroot should change the root filesystem for you. > (look in the manpages for more details) > > As for powering down the hdd I did find a page for this, > but havent had time to play with it yet: > http://www.cran.org.uk/bruce/software.php there is a port "ataidle" that sets teh IDE drive's internal idle timeout timer so it will spin down if you dont use it.. as for scsi, you can sent it a spin-down command with camcontrol but I forget the actual command.. (it should be in the scsi .h files) julian > > best of luck! > > > Hello, > > > > in an attempt to save power on FreeBSD servers, I'm > > trying to replace the hdd with a ramdisk. The idea is to: > > > > 1. boot from the hdd (or netboot from an NFS server) > > 2. configure a ram disk (md(4)) > > 3. copy everything that's needed to ram disk > > 4. transfer kernel root to ramdisk (*) > > 5. turn off the hdd (**) > > > > (*) is the hairy question. > > (**) How can that be done? > > > > I won't need paging, because there'll be enough ram for > > everything (ramdisk, kernel and userland). > > > > Now the questions are: > > > > * How to "attach" the root filesystem to the ram disk? > > > > Can this be done only through pxe/netboot before the > > kernel starts, or is there some kind of system call > > that can transfer root on a running system? > > > > * How to power off (and on) the hdd (both for ATA and SCSI)? > > > > * Will the power consumption decrease (no hdd) or will > > it increase (more ram)? Anybody measured this before > > with regular diskless machines? > > > > Thanks, > > -cpghost. > > > > > _______________________________________________ > freebsd-multimedia@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-multimedia > To unsubscribe, send any mail to "freebsd-multimedia-unsubscribe@freebsd.org" >
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