Okay so its been a while so I figured I'd better update on things. It Works! I've gotten it to work using Val's documentation at http://valerieaurora.org/union/ with some additions to the initramfs package to generate the correct initrd # cat etc/initramfs-tools/scripts/nfs-bottom/union #!/bin/sh # init-premount script for lvm2. PREREQS="" prereqs() { echo $PREREQS } case "$1" in prereqs) prereqs exit 0 ;; esac echo "mounting union tmpfs" mount.union -n -o union -t tmpfs none ${rootmnt} # cat etc/initramfs-tools/hooks/union #!/bin/sh PREREQ="" prereqs() { echo "$PREREQ" } case $1 in prereqs) prereqs exit 0 ;; esac . /usr/share/initramfs-tools/hook-functions copy_exec /bin/mount /bin/mount.union # Then it works pretty good. (I really like debians initramfs package). I can stand up an 8 node cluster with an nfs read only root file system and it works! However, the output of the kernel is very verbose lots of debug messages about how you are managing the tmpfs part of the union. Also lots of duplicate entries, which seems weird. May 21 21:53:24 x6 kernel: [ 56.558749] lib: appending to union Does this mean you are appending /lib to the union tmpfs over and over? So df doesn't show any leaking of the processes running on the system syslog is going over the wire to a central server, there's 7 agetty's running, udev is kinda freaking out (kernel version difference I guess), and cron is running. So the image is pretty stripped down. This is pretty usual for an HPC compute node. I'm currently doing some long tests trying to determine how fast would tmpfs fill up and what would be filling it up. Also, when is it going to be included to mainline stuff? Also, should I put a redhat bugzilla request in for inclusion into RHEL 6.1/2? Sadly, this wonderful feature would be more easily adopted here if it was included into RHEL 6.1 or 6.2 at some point. Thanks, - David Brown -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
