在持久实时启动系统 (ubuntu 16.04 LTS) 中执行 sudo apt 更新时出错

Question

我在尝试安装 opencv 和 python 包时执行 sudo apt-get update 时遇到以下问题：

root@ubuntu:~# apt-get update
Ign:1 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial InRelease
Hit:2 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial Release Ign:4 http://dl.google.com/linux/chrome/deb stable InRelease Hit:5 http://dl.google.com/linux/chrome/deb stable Release Get:6 http://security.ubuntu.com/ubuntu xenial-security InRelease [102 kB] Hit:8 http://archive.ubuntu.com/ubuntu xenial InRelease Get:9 http://archive.ubuntu.com/ubuntu xenial-updates InRelease [102 kB] Get:10 http://security.ubuntu.com/ubuntu xenial-security/main amd64 DEP-11 Metadata [60.2 kB] Ign:11 http://www.openprinting.org/download/printdriver/debian lsb3.2 InRelease Get:12 http://security.ubuntu.com/ubuntu xenial-security/main DEP-11 64x64 Icons [57.6 kB] Get:13 http://security.ubuntu.com/ubuntu xenial-security/universe amd64 DEP-11 Metadata [49.7 kB] Get:14 http://security.ubuntu.com/ubuntu xenial-security/universe DEP-11 64x64 Icons [80.0 kB] Hit:15 http://www.openprinting.org/download/printdriver/debian lsb3.2 Release Get:17 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 DEP-11 Metadata [305 kB] Get:18 http://archive.ubuntu.com/ubuntu xenial-updates/main DEP-11 64x64 Icons [217 kB] Get:19 http://archive.ubuntu.com/ubuntu xenial-updates/universe amd64 DEP-11 Metadata [173 kB] Get:20 http://archive.ubuntu.com/ubuntu xenial-updates/universe DEP-11 64x64 Icons [240 kB] Get:21 http://archive.ubuntu.com/ubuntu xenial-updates/multiverse amd64 DEP-11 Metadata [5,892 B]
Fetched 1,392 kB in 1s (1,068 kB/s)
** (appstreamcli:7142): CRITICAL **: Error while moving old database out of the way.
AppStream cache update failed.
Reading package lists... Done W: http://www.openprinting.org/download/printdriver/debian/dists/lsb3.2/Release.gpg: Signature by key F8897B6F00075648E248B7EC24CBF5474CFD1E2F uses weak digest algorithm (SHA1) 

为了缓解 AppStream 缓存问题，我参考了这篇文章：无法在持久的 Ubuntu 16.04 USB 上“apt-get dist-upgrade”并运行以下命令：

root@ubuntu:~# sudo chmod -R a+rX,u+w /var/cache/app-info/xapian/default
root@ubuntu:~# apt-get update
Ign:1 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial InRelease
Hit:2 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial Release Ign:4 http://dl.google.com/linux/chrome/deb stable InRelease Hit:5 http://dl.google.com/linux/chrome/deb stable Release Hit:7 http://security.ubuntu.com/ubuntu xenial-security InRelease Hit:8 http://archive.ubuntu.com/ubuntu xenial InRelease Hit:9 http://archive.ubuntu.com/ubuntu xenial-updates InRelease Ign:10 http://www.openprinting.org/download/printdriver/debian lsb3.2 InRelease Hit:11 http://www.openprinting.org/download/printdriver/debian lsb3.2 Release
Reading package lists... Done W: http://www.openprinting.org/download/printdriver/debian/dists/lsb3.2/Release.gpg: Signature by key F8897B6F00075648E248B7EC24CBF5474CFD1E2F uses weak digest algorithm (SHA1)

我不确定究竟是什么导致了这个问题。因此，我也尝试了 apt get upgrade 并在我的命令行中得到以下内容：

root@ubuntu:~# apt-get upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following packages have been kept back:
gnome-software gnome-software-common libegl1-mesa libgbm1 libgl1-mesa-dri libinput10 libmirclient9 libwayland-egl1-mesa libxatracker2
linux-generic-hwe-16.04 linux-headers-generic-hwe-16.04 linux-image-generic-hwe-16.04 linux-signed-generic-hwe-16.04
linux-signed-image-generic-hwe-16.04 python3-software-properties python3-update-manager software-properties-common software-properties-gtk
ubuntu-software update-manager update-manager-core update-notifier update-notifier-common xserver-xorg-core-hwe-16.04
xserver-xorg-hwe-16.04 xserver-xorg-input-evdev-hwe-16.04 xserver-xorg-input-synaptics-hwe-16.04 xserver-xorg-input-wacom-hwe-16.04
xserver-xorg-video-amdgpu-hwe-16.04 xserver-xorg-video-ati-hwe-16.04 xserver-xorg-video-fbdev-hwe-16.04 xserver-xorg-video-intel-hwe-16.04
xserver-xorg-video-nouveau-hwe-16.04 xserver-xorg-video-qxl-hwe-16.04 xserver-xorg-video-radeon-hwe-16.04 xserver-xorg-video-vesa-hwe-16.04
xserver-xorg-video-vmware-hwe-16.04
0 upgraded, 0 newly installed, 0 to remove and 37 not upgraded.
3 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Do you want to continue? [Y/n] Y
Setting up cryptsetup (2:1.6.6-5ubuntu2.1) ...
update-initramfs is disabled since running on read-only media
update-rc.d: warning: start and stop actions are no longer supported; falling back to defaults
insserv: Service checkroot has to be enabled to start service cryptdisks-early
insserv: exiting now!
update-rc.d: error: insserv rejected the script header
dpkg: error processing package cryptsetup (--configure):
subprocess installed post-installation script returned error exit status 1
dpkg: dependency problems prevent configuration of ubiquity:
ubiquity depends on cryptsetup; however:
Package cryptsetup is not configured yet.
dpkg: error processing package ubiquity (--configure):
dependency problems - leaving unconfigured
dpkg: dependency problems prevent configuration of ubiquity-frontend-gtk:
ubiquity-frontend-gtk depends on ubiquity (= 2.21.63.4); however:
Package ubiquity is not configured yet.
dpkg: error processing package ubiquity-frontend-gtk (--configure):
dependency problems - leaving unconfigured
No apport report written because the error message indicates its a followup error from a previous failure.
No apport report written because the error message indicates its a followup error from a previous failure.
Errors were encountered while processing:
cryptsetup
ubiquity
ubiquity-frontend-gtk
E: Sub-process /usr/bin/dpkg returned an error code (1) 

我还尝试了以下命令（参考：https : //askubuntu.com/a/899786/484475）：

root@ubuntu:~# sudo apt-get autoremove && sudo apt-get autoclean
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 37 not upgraded.
3 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Setting up cryptsetup (2:1.6.6-5ubuntu2.1) ...
update-initramfs is disabled since running on read-only media
update-rc.d: warning: start and stop actions are no longer supported; falling back to defaults
insserv: Service checkroot has to be enabled to start service cryptdisks-early
insserv: exiting now!
update-rc.d: error: insserv rejected the script header
dpkg: error processing package cryptsetup (--configure):
subprocess installed post-installation script returned error exit status 1
dpkg: dependency problems prevent configuration of ubiquity:
ubiquity depends on cryptsetup; however:
Package cryptsetup is not configured yet.
dpkg: error processing package ubiquity (--configure):
dependency problems - leaving unconfigured
dpkg: dependency problems prevent configuration of ubiquity-frontend-gtk:
ubiquity-frontend-gtk depends on ubiquity (= 2.21.63.4); however:
Package ubiquity is not configured yet.
dpkg: error processing package ubiquity-frontend-gtk (--configure):
dependency problems - leaving unconfigured
No apport report written because the error message indicates its a followup error from a previous failure.
No apport report written because the error message indicates its a followup error from a previous failure.
Errors were encountered while processing:
cryptsetup
ubiquity
ubiquity-frontend-gtk
E: Sub-process /usr/bin/dpkg returned an error code (1) 

我再次提到另一个链接update-rc.d: error: insserv denied the script header dpkg: erreur de traitement du paquet util-linux (--configure) :但我没有发现缺少 cryptsetup 的 init 头。另一个答案说问题在于启动顺序：https : //unix.stackexchange.com/questions/289667/unable-to-install-anything-using-apt-get-because-of-insserv但我不能查找标题的任何问题。我推断包之间存在依赖关系，因此尝试了以下命令（参考链接：执行 sudo-apt upgrade 时出现 cryptsetup 错误）：

root@ubuntu:~# sudo dpkg --configure cryptsetup
Setting up cryptsetup (2:1.6.6-5ubuntu2.1) ...
update-initramfs is disabled since running on read-only media
update-rc.d: warning: start and stop actions are no longer supported; falling back to defaults
insserv: Service checkroot has to be enabled to start service cryptdisks-early
insserv: exiting now!
update-rc.d: error: insserv rejected the script header
dpkg: error processing package cryptsetup (--configure):
subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
Cryptsetup 

解决问题的另一种尝试：

root@ubuntu:~# sudo dpkg --configure --pending
Setting up cryptsetup (2:1.6.6-5ubuntu2.1) ...
update-initramfs is disabled since running on read-only media
update-rc.d: warning: start and stop actions are no longer supported; falling back to defaults
insserv: Service checkroot has to be enabled to start service cryptdisks-early
insserv: exiting now!
update-rc.d: error: insserv rejected the script header
dpkg: error processing package cryptsetup (--configure):
subprocess installed post-installation script returned error exit status 1
dpkg: dependency problems prevent configuration of ubiquity:
ubiquity depends on cryptsetup; however:
Package cryptsetup is not configured yet.
dpkg: error processing package ubiquity (--configure):
dependency problems - leaving unconfigured
dpkg: dependency problems prevent configuration of ubiquity-frontend-gtk:
ubiquity-frontend-gtk depends on ubiquity (= 2.21.63.4); however:
Package ubiquity is not configured yet.
dpkg: error processing package ubiquity-frontend-gtk (--configure):
dependency problems - leaving unconfigured
Errors were encountered while processing:
cryptsetup
ubiquity
ubiquity-frontend-gtk 

我尝试的任何事情（包括干净的声明）都会将我重定向到相同的问题：

Errors were encountered while processing:
cryptsetup
ubiquity
ubiquity-frontend-gtk

作为最后一次尝试，我尝试搜索问题所在，并在网上找到了这个https://superuser.com/questions/903142/how-to-run-update-initramfs-from-bootable-usb以检查导致update-initramfs is disabled since running on read-only media问题并找到了我无法掌握的解决方案。

sudo dpkg --configure cryptsetup
Setting up cryptsetup (2:1.6.6-5ubuntu2.1) ...
update-initramfs is disabled since running on read-only media
update-rc.d: warning: start and stop actions are no longer supported; falling back to defaults
insserv: Service checkroot has to be enabled to start service cryptdisks-early
insserv: exiting now!
update-rc.d: error: insserv rejected the script header
dpkg: error processing package cryptsetup (--configure):
 subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
 cryptsetup

由于 dpkg 重新配置 cryptsetup 取决于 checkroot，我不确定要做什么。我把checkroot.sh的内容贴出来了：

#! /bin/sh
### BEGIN INIT INFO
# Provides:          checkroot mtab
# Required-Start:    mountdevsubfs hostname
# Required-Stop:     
# Should-Start:      keymap hwclockfirst hdparm bootlogd
# Should-stop:
# Default-Start:     S
# Default-Stop:
# X-Interactive:     true
# Short-Description: Check to root file system.
### END INIT INFO
# Include /usr/bin in path to find on_ac_power if /usr/ is on the root
# partition.
PATH=/sbin:/bin:/usr/bin
FSCK_LOGFILE=/var/log/fsck/checkroot
[ "$FSCKFIX" ] || FSCKFIX=no
[ "$SULOGIN" ] || SULOGIN=no
. /lib/init/vars.sh
. /lib/lsb/init-functions
. /lib/init/mount-functions.sh
do_start () {
    # Trap SIGINT so that we can handle user interrupt of fsck.
    trap "" INT
    #
    # Set SULOGIN in /etc/default/rcS to yes if you want a sulogin to
    # be spawned from this script *before anything else* with a timeout,
    # like sysv does.
    #
    [ "$SULOGIN" = yes ] && sulogin -t 30 $CONSOLE
    KERNEL="$(uname -s)"
    MACHINE="$(uname -m)"
    read_fstab
    #
    # Activate the swap device(s) in /etc/fstab. This needs to be done
    # before fsck, since fsck can be quite memory-hungry.
    #
    ENABLE_SWAP=no
    case "$KERNEL" in
      Linux)
        if [ "$NOSWAP" = yes ]
        then
            [ "$VERBOSE" = no ] || log_warning_msg "Not activating swap as requested via bootoption noswap."
            ENABLE_SWAP=no
        else
            if [ "$swap_on_lv" = yes ]
            then
                [ "$VERBOSE" = no ] || log_warning_msg "Not activating swap on logical volume."
            elif [ "$swap_on_file" = yes ]
            then
                [ "$VERBOSE" = no ] || log_warning_msg "Not activating swap on swapfile."
            else
                ENABLE_SWAP=yes
            fi
        fi
        ;;
      *)
        ENABLE_SWAP=yes
        ;;
    esac
    if [ "$ENABLE_SWAP" = yes ]
    then
        if [ "$VERBOSE" = no ]
        then
            log_action_begin_msg "Activating swap"
            swapon -a -e >/dev/null 2>&1
            log_action_end_msg $?
        else
            log_daemon_msg "Activating swap"
            swapon -a -v
            log_end_msg $?
        fi
    fi
    #
    # Does the root device in /etc/fstab match with the actual device ?
    # If not we try to use the /dev/root alias device, and if that
    # fails we create a temporary node in /run.
    #
    # Do this only on Linux. Neither kFreeBSD nor Hurd have
    # /dev/root and the device ids used here are specific to
    # Linux.
    KERNEL="$(uname)"
    if [ "$rootcheck" = yes ] && [ "$KERNEL" = Linux ]
    then
        ddev="$(mountpoint -qx $rootdev)"
        rdev="$(mountpoint -d /)"
        if [ "$ddev" != "$rdev" ] && [ "$ddev" != "4:0" ]
        then
            if [ "$(mountpoint -qx /dev/root)" = "4:0" ]
            then
                rootdev=/dev/root
            else
                if \
                    rm -f /run/rootdev \
                    && mknod -m 600 /run/rootdev b ${rdev%:*} ${rdev#*:} \
                    && [ -e /run/rootdev ]
                then
                    rootdev=/run/rootdev
                else
                    rootfatal=yes
                fi
            fi
        fi
    fi
    #
    # Bother, said Pooh.
    #
    if [ "$rootfatal" = yes ]
    then
        log_failure_msg "The device node $rootdev for the root filesystem is missing or incorrect 
or there is no entry for the root filesystem listed in /etc/fstab. 
The system is also unable to create a temporary node in /run. 
This means you have to fix the problem manually."
        log_warning_msg "A maintenance shell will now be started. 
CONTROL-D will terminate this shell and restart the system."
        # Start a single user shell on the console
        if ! sulogin $CONSOLE
        then
            log_failure_msg "Attempt to start maintenance shell failed. 
Will restart in 5 seconds."
            sleep 5
        fi
        [ "$VERBOSE" = no ] || log_action_msg "Will now restart"
        reboot -f
    fi
    # See if we're on AC Power.  If not, we're not gonna run our
    # check.  If on_ac_power (in /usr/) is unavailable, behave as
    # before and check all file systems needing it.
# Disabled AC power check until fsck can be told to only check the
# file system if it is corrupt when running on battery. (bug #526398)
#   if which on_ac_power >/dev/null 2>&1 && [ "$rootcheck" = yes ]
#   then
#       on_ac_power >/dev/null 2>&1
#       if [ "$?" -eq 1 ]
#       then
#           log_warning_msg "On battery power, so skipping file system check."
#           rootcheck=no
#       fi
#   fi
    #
    # See if we want to check the root file system.
    #
    FSCKCODE=0
    if [ -e /run/initramfs/fsck-root ]
    then
        rootcheck=no
    fi
    if is_fastboot_active
    then
        [ "$rootcheck" = yes ] && log_warning_msg "Fast boot enabled, so skipping root file system check."
        rootcheck=no
    fi
    if which findmnt >/dev/null 2>&1
    then
        if [ "$(findmnt -f -n -o FSTYPE /)" = "btrfs" ]
        then
            [ "$rootcheck" = yes ] && log_warning_msg "btrfs root detected, so skipping root file system check."
            rootcheck=no
        fi
    fi
    if [ "$rootcheck" = yes ]
    then
        #
        # Ensure that root is quiescent and read-only before fsck'ing.
        #
        # mount -n -o remount,ro / would be the correct syntax but
        # mount can get confused when there is a "bind" mount defined
        # in fstab that bind-mounts "/" somewhere else.
        #
        # So we use mount -n -o remount,ro $rootdev / but that can
        # fail on older kernels on sparc64/alpha architectures due
        # to a bug in sys_mount().
        #
        # As a compromise we try both.
        #
        if \
            ! mount    -n -o remount,ro              $rootdev /              \
            && ! mount -n -o remount,ro -t dummytype $rootdev /  2>/dev/null \
            && ! mount -n -o remount,ro                       /  2>/dev/null
        then
            log_failure_msg "Cannot check root file system because it is not mounted read-only."
            rootcheck=no
        fi
    fi
    #
    # The actual checking is done here.
    #
    if [ "$rootcheck" = yes ]
    then
        if [ -f /forcefsck ] || grep -q -s -w -i "forcefsck" /proc/cmdline
        then
            force="-f"
        else
            force=""
        fi
        if [ "$FSCKFIX" = yes ]
        then
            fix="-y"
        else
            fix="-a"
        fi
        spinner="-C"
        case "$TERM" in
          dumb|network|unknown|"")
            spinner="" ;;
        esac
        # This Linux/s390x special case should go away.
        if [ "${KERNEL}:${MACHINE}" = Linux:s390x ]
        then
            spinner=""
        fi
        if [ "$VERBOSE" = no ]
        then
            log_action_begin_msg "Checking root file system"
            logsave -s $FSCK_LOGFILE fsck $spinner $force $fix -t $roottype $rootdev
            FSCKCODE=$?
            if [ "$FSCKCODE" = 0 ]
            then
                log_action_end_msg 0
            else
                log_action_end_msg 1 "code $FSCKCODE"
            fi
        else
            log_daemon_msg "Will now check root file system"
            logsave -s $FSCK_LOGFILE fsck $spinner $force $fix -V -t $roottype $rootdev
            FSCKCODE=$?
            log_end_msg $FSCKCODE
        fi
    fi
    #
    # If there was a failure, drop into single-user mode.
    #
    # NOTE: "failure" is defined as exiting with a return code of
    # 4 or larger. A return code of 1 indicates that file system
    # errors were corrected but that the boot may proceed. A return
    # code of 2 or 3 indicates that the system should immediately reboot.
    #
    if [ "$FSCKCODE" -eq 32 ]
    then
        log_warning_msg "File system check was interrupted by user"
    elif [ "$FSCKCODE" -gt 3 ]
    then
        # Surprise! Re-directing from a HERE document (as in "cat << EOF")
        # does not work because the root is currently read-only.
        log_failure_msg "An automatic file system check (fsck) of the root 

    

Answer 1

简单的答案是您正在滥用持久性机制，您需要停止 =)

更长的答案是持久性使用 COW（写时复制）机制 - https://en.wikipedia.org/wiki/Copy-on-write

抱歉提供维基百科链接 =)

所以iso（技术上是根文件系统，squashfs）是一个只读文件系统。这个“iso”或根文件系统永远不能改变或重新制作iso。

输入持久性的想法，如果您愿意，这是一种创建叠加层的机制。因此，如果您更新系统或进行更改，则会对文件（持久性）而不是 iso 进行更改。

这适用于简单的任务，例如调整界面、自定义桌面、保存一些数据、保存无线密码。

但是 COW 系统崩溃了，您在更改中进行更改。所以你有一个基本的 RO 文件系统，你sudo apt-update一遍又一遍地运行，COW 系统不是一个数据库，可以将所有这些更改添加到更改中并最终失败。

解决方法是：

1. 谨慎使用 Persistence，并尽可能少做更改，可能会存储用户设置、无线密码，并一次性安装一些应用程序。但是不要滥用它，将其视为已安装的系统并尝试运行sudo apt update && sudo apt upgrade，COW 无法处理数百个包的多次更改。

2. 只需进行常规安装。可能是最好的主意，因为您显然打算继续使用 Ubuntu。

希望答案不会太技术性，也希望我没有把情况简化太多。