root@robinson:~# update-initramfs -u
update-initramfs: Generating /boot/initrd.img-4.19.0-14-amd64
W: Possible missing firmware /lib/firmware/nvidia/gv100/acr/ucode_load.bin for module nouveau
live-boot: core filesystems devices utils udev blockdev dns.
root@robinson:~# 

root@robinson:~# lsinitramfs /initrd.img | grep resume
conf/conf.d/resume
conf/conf.d/zz-resume-auto
scripts/local-premount/resume
usr/bin/resume
root@robinson:~# lsinitramfs /initrd.img | grep resume

computerbob@robinson:~$ su -
Password: 
root@robinson:~# df
Filesystem     1K-blocks      Used Available Use% Mounted on
udev             6131508         0   6131508   0% /dev
tmpfs            1229144      1080   1228064   1% /run
/dev/sda1        8987368   4117432   4393676  49% /
tmpfs               5120         4      5116   1% /run/lock
tmpfs            2578500       924   2577576   1% /dev/shm
/dev/sda2        8813184   3119228   5226552  38% /home
/dev/sda6      258857292 102270356 144674464  42% /media/data
none             6145708         0   6145708   0% /run/user/1000
/dev/sdb1        1669504   1669504         0 100% /media/computerbob/liveiso
root@robinson:~# 

root@robinson:~# fdisk -l
Disk /dev/sda: 279.5 GiB, 300069052416 bytes, 586072368 sectors
Disk model: WDC WD3000HLFS-7
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: 4ECAB59F-E177-402A-8228-77D09EB1E966

Device        Start       End   Sectors   Size Type
/dev/sda1      2048  18397183  18395136   8.8G Linux filesystem
/dev/sda2  18397184  36438015  18040832   8.6G Linux filesystem
/dev/sda3  36438016  37640191   1202176   587M Linux swap
/dev/sda6  57970688 586072063 528101376 251.8G Linux filesystem

Disk /dev/sdb: 3.7 GiB, 4004511744 bytes, 7821312 sectors
Disk model: Cruzer          
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x3d2c28bb

Device     Boot Start     End Sectors  Size Id Type
/dev/sdb1  *       64 3339071 3339008  1.6G 17 Hidden HPFS/NTFS
root@robinson:~# 

#!/bin/sh

# Default PATH differs between shells, and is not automatically exported
# by klibc dash.  Make it consistent.
export PATH=/sbin:/usr/sbin:/bin:/usr/bin

[ -d /dev ] || mkdir -m 0755 /dev
[ -d /root ] || mkdir -m 0700 /root
[ -d /sys ] || mkdir /sys
[ -d /proc ] || mkdir /proc
[ -d /tmp ] || mkdir /tmp
mkdir -p /var/lock
mount -t sysfs -o nodev,noexec,nosuid sysfs /sys
mount -t proc -o nodev,noexec,nosuid proc /proc

# shellcheck disable=SC2013
for x in $(cat /proc/cmdline); do
    case $x in
    initramfs.clear)
        clear
        ;;
    quiet)
        quiet=y
        ;;
    esac
done

if [ "$quiet" != "y" ]; then
    quiet=n
    echo "Loading, please wait..."
fi
export quiet

# Note that this only becomes /dev on the real filesystem if udev's scripts
# are used; which they will be, but it's worth pointing out
mount -t devtmpfs -o nosuid,mode=0755 udev /dev
mkdir /dev/pts
mount -t devpts -o noexec,nosuid,gid=5,mode=0620 devpts /dev/pts || true

# Export the dpkg architecture
export DPKG_ARCH=
. /conf/arch.conf

# Set modprobe env
export MODPROBE_OPTIONS="-qb"

# Export relevant variables
export ROOT=
export ROOTDELAY=
export ROOTFLAGS=
export ROOTFSTYPE=
export IP=
export DEVICE=
export BOOT=
export BOOTIF=
export UBIMTD=
export break=
export init=/sbin/init
export readonly=y
export rootmnt=/root
export debug=
export panic=
export blacklist=
export resume=
export resume_offset=
export noresume=
export drop_caps=
export fastboot=n
export forcefsck=n
export fsckfix=

# Bring in the main config
. /conf/initramfs.conf
for conf in conf/conf.d/*; do
    [ -f "${conf}" ] && . "${conf}"
done
. /scripts/functions

# Parse command line options
# shellcheck disable=SC2013
for x in $(cat /proc/cmdline); do
    case $x in
    init=*)
        init=${x#init=}
        ;;
    root=*)
        ROOT=${x#root=}
        if [ -z "${BOOT}" ] && [ "$ROOT" = "/dev/nfs" ]; then
            BOOT=nfs
        fi
        ;;
    rootflags=*)
        ROOTFLAGS="-o ${x#rootflags=}"
        ;;
    rootfstype=*)
        ROOTFSTYPE="${x#rootfstype=}"
        ;;
    rootdelay=*)
        ROOTDELAY="${x#rootdelay=}"
        case ${ROOTDELAY} in
        *[![:digit:].]*)
            ROOTDELAY=
            ;;
        esac
        ;;
    nfsroot=*)
        # shellcheck disable=SC2034
        NFSROOT="${x#nfsroot=}"
        ;;
    initramfs.runsize=*)
        RUNSIZE="${x#initramfs.runsize=}"
        ;;
    ip=*)
        IP="${x#ip=}"
        ;;
    boot=*)
        BOOT=${x#boot=}
        ;;
    ubi.mtd=*)
        UBIMTD=${x#ubi.mtd=}
        ;;
    resume=*)
        RESUME="${x#resume=}"
        case $RESUME in
        UUID=*)
            RESUME="/dev/disk/by-uuid/${RESUME#UUID=}"
        esac
        ;;
    resume_offset=*)
        resume_offset="${x#resume_offset=}"
        ;;
    noresume)
        noresume=y
        ;;
    drop_capabilities=*)
        drop_caps="-d ${x#drop_capabilities=}"
        ;;
    panic=*)
        panic="${x#panic=}"
        case ${panic} in
        *[![:digit:].]*)
            panic=
            ;;
        esac
        ;;
    ro)
        readonly=y
        ;;
    rw)
        readonly=n
        ;;
    debug)
        debug=y
        quiet=n
        if [ -n "${netconsole}" ]; then
            log_output=/dev/kmsg
        else
            log_output=/run/initramfs/initramfs.debug
        fi
        set -x
        ;;
    debug=*)
        debug=y
        quiet=n
        set -x
        ;;
    break=*)
        break=${x#break=}
        ;;
    break)
        break=premount
        ;;
    blacklist=*)
        blacklist=${x#blacklist=}
        ;;
    netconsole=*)
        netconsole=${x#netconsole=}
        [ "x$debug" = "xy" ] && log_output=/dev/kmsg
        ;;
    BOOTIF=*)
        BOOTIF=${x#BOOTIF=}
        ;;
    fastboot|fsck.mode=skip)
        fastboot=y
        ;;
    forcefsck|fsck.mode=force)
        forcefsck=y
        ;;
    fsckfix|fsck.repair=yes)
        fsckfix=y
        ;;
    fsck.repair=no)
        fsckfix=n
        ;;
    esac
done

# Default to BOOT=local if no boot script defined.
if [ -z "${BOOT}" ]; then
    BOOT=local
fi

if [ -n "${noresume}" ] || [ "$RESUME" = none ]; then
    noresume=y
else
    resume=${RESUME:-}
fi

mount -t tmpfs -o "noexec,nosuid,size=${RUNSIZE:-10%},mode=0755" tmpfs /run
mkdir -m 0755 /run/initramfs

if [ -n "$log_output" ]; then
    exec >$log_output 2>&1
    unset log_output
fi

maybe_break top

# Don't do log messages here to avoid confusing graphical boots
run_scripts /scripts/init-top

maybe_break modules
[ "$quiet" != "y" ] && log_begin_msg "Loading essential drivers"
[ -n "${netconsole}" ] && modprobe netconsole netconsole="${netconsole}"
load_modules
[ "$quiet" != "y" ] && log_end_msg

if [ "$ROOTDELAY" ]; then
    sleep $ROOTDELAY
fi

maybe_break premount
[ "$quiet" != "y" ] && log_begin_msg "Running /scripts/init-premount"
run_scripts /scripts/init-premount
[ "$quiet" != "y" ] && log_end_msg

maybe_break mount
log_begin_msg "Mounting root file system"
# Always load local and nfs (since these might be needed for /etc or
# /usr, irrespective of the boot script used to mount the rootfs).
. /scripts/local
. /scripts/nfs
. /scripts/${BOOT}
parse_numeric "${ROOT}"
maybe_break mountroot
mount_top
mount_premount
mountroot
log_end_msg

if read_fstab_entry /usr; then
    log_begin_msg "Mounting /usr file system"
    mountfs /usr
    log_end_msg
fi

# Mount cleanup
mount_bottom
nfs_bottom
local_bottom

maybe_break bottom
[ "$quiet" != "y" ] && log_begin_msg "Running /scripts/init-bottom"
# We expect udev's init-bottom script to move /dev to ${rootmnt}/dev
run_scripts /scripts/init-bottom
[ "$quiet" != "y" ] && log_end_msg

# Move /run to the root
mount -n -o move /run ${rootmnt}/run

validate_init() {
    run-init -n "${rootmnt}" "${1}"
}

# Check init is really there
if ! validate_init "$init"; then
    echo "Target filesystem doesn't have requested ${init}."
    init=
    for inittest in /sbin/init /etc/init /bin/init /bin/sh; do
        if validate_init "${inittest}"; then
            init="$inittest"
            break
        fi
    done
fi

# No init on rootmount
if ! validate_init "${init}" ; then
    panic "No init found. Try passing init= bootarg."
fi

maybe_break init

# don't leak too much of env - some init(8) don't clear it
# (keep init, rootmnt, drop_caps)
unset debug
unset MODPROBE_OPTIONS
unset DPKG_ARCH
unset ROOTFLAGS
unset ROOTFSTYPE
unset ROOTDELAY
unset ROOT
unset IP
unset BOOT
unset BOOTIF
unset DEVICE
unset UBIMTD
unset blacklist
unset break
unset noresume
unset panic
unset quiet
unset readonly
unset resume
unset resume_offset
unset noresume
unset fastboot
unset forcefsck
unset fsckfix

# Move virtual filesystems over to the real filesystem
mount -n -o move /sys ${rootmnt}/sys
mount -n -o move /proc ${rootmnt}/proc

# Chain to real filesystem
# shellcheck disable=SC2086,SC2094
exec run-init ${drop_caps} "${rootmnt}" "${init}" "$@" <"${rootmnt}/dev/console" >"${rootmnt}/dev/console" 2>&1
echo "Something went badly wrong in the initramfs."
panic "Please file a bug on initramfs-tools."

cat /home/snapshot/snapshot-20210311_1353.iso > /dev/sdb

random: crng init done

cat /home/snapshot/snapshot-20210311_1353.iso> /dev/sdb

Begin: running /scripts/live-pre(something I don''t remember)... done
random: fast-init done
random: crng init done
random: 4 urandom warning(s) missed due to rate limiting