Date: Mon, 25 Apr 2005 09:59:36 +0200 From: "Emmanuel Chriqui" <wingman@waika9.com> To: <freebsd-stable@freebsd.org> Subject: Re: PXEBOOT/TFTPBOOT + big MD_ROOT problem Message-ID: <20050425075855.BB485C07C@postfix3-2.free.fr>
next in thread | raw e-mail | index | archive | help
> I'm trying to make very big MD_ROOT (300MB) sent using > PXEBOOT+TFTPBOOT. No NFS. It's a sort of diskless machine with all the > system on ram. There is a problem when the preloaded image is >~32MB. > Kernel loads but it does not seem to find the files. It seems as if > only part of the image is really there. With a "small" image (<~32MB), > no probleme. I use the same image, off course, same init etc... just > more data for my application in the big image case. > > I use a classic mfs_root approche to make my image > > dd if=/dev/zero of=$MFS_FILE bs=1k count=$SIZE mdconfig -a -t vnode -f > $MFS_FILE -u0 bsdlabel -w /dev/md0 newfs /dev/md0a mount /dev/md0a > $MFS_FILE_MOUNT cp ... my content... > umount $MFS_FILE_MOUNT > fsck -t ufs /dev/md0a > mdconfig -d -u 0 > > then I mount the $MFS_FILE_MOUNT . > > I use i386/5.4RC2/TFTPD/PXEBOOT+TFTPBOOT . > (same pb with a 5.3). > > Am I missing something obvious? > It seems not. There seems to be a size limitation in the loader (and pxeboot since it is built using loader code). I've tried loading through pxeboot + TFTP : the tftp pxeboot client is limited to 32MB unfortunately (BTW : the one of the tftp port works fine). I tried to use pxeboot + NFS, kernel hangs because of loader limitation (BTW : you can use only NFS UDP since the pxeboot NFS client don't do TCP which means booting using this this technique using TFTP is not less reliable than NFS). I even tried pxegrub, but again it's the loader ... It seems the only reasonable solution is to make a small jumpstart mfsroot, make a md device (malloc / ..) with any size you want as long as you have enough memory (even 1GB+) and then fetch the mfsroot image using tftp/nfs/scp/.. and chroot to it. Emmanuel.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20050425075855.BB485C07C>