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How to mount a non root filesystem early in the boot process

Environment

  • Red Hat Enterprise Linux 7

Issue

Resolution

  • Create /etc/fstab.sys
Raw
# vi /etc/fstab.sys
UUID="71be1001-d764-4505-a225-30d4771833f5" /mnt/test xfs    defaults 0 0
fstab.sys uses the same syntax style as /etc/fstab
  • Rebuild initramfs
Raw
# dracut -f
  • Reboot
Raw
# reboot

Root Cause

The dracut fstab-sys module allows the ability to load a seperate fstab into the initramfs which can allow the ability to load a file system earlier in the boot process.
/usr/lib/dracut/modules.d/95fstab-sys/module-setup.sh
Raw
#!/bin/bash
# -*- mode: shell-script; indent-tabs-mode: nil; sh-basic-offset: 4; -*-
# ex: ts=8 sw=4 sts=4 et filetype=sh

check() {
    test -f /etc/fstab.sys || [[ -n $add_fstab  ||  -n $fstab_lines ]]
}

depends() {
    echo fs-lib
}

install() {
    [ -f /etc/fstab.sys ] && inst_simple /etc/fstab.sys
    inst_hook pre-pivot 00 "$moddir/mount-sys.sh"
}

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