boot – Ubuntu Crash: systemd-journal Error writing the entry. Ignoring: read-only file system

I'm in Ubuntu 18.04.3 LTS, Gnome 3.28.2 No dual boot and no external USB devices. Occasionally a black terminal screen appears with this error information.

When I get this black screen, the computer no longer responds and I have to restart with the power button.

Hardware and operating system information:

(base) x@x:~$ df
Filesystem                  1K-blocks     Used Available Use% Mounted on
udev                          8074028        0   8074028   0% /dev
tmpfs                         1621272     2176   1619096   1% /run
/dev/mapper/ubuntu--vg-root 113125620 97117896  10218236  91% /
tmpfs                         8106348   126836   7979512   2% /dev/shm
tmpfs                            5120        4      5116   1% /run/lock
tmpfs                         8106348        0   8106348   0% /sys/fs/cgroup
/dev/loop3                       1024     1024         0 100% /snap/gnome-logs/61
/dev/loop2                      69248    69248         0 100% /snap/sublime-text/67
/dev/loop1                       4224     4224         0 100% /snap/gnome-calculator/406
/dev/sda1                      720368   150420    517556  23% /boot
/dev/loop4                      90880    90880         0 100% /snap/core/7396
/dev/loop5                     141696   141696         0 100% /snap/thunderbird/29
/dev/loop7                     224256   224256         0 100% /snap/gimp/165
/dev/loop8                      88448    88448         0 100% /snap/ubuntu-mate-welcome/335
/dev/loop11                     19200    19200         0 100% /snap/communitheme/1593
/dev/loop10                     58368    58368         0 100% /snap/powershell/36
/dev/loop12                    268544   268544         0 100% /snap/gnss-sdr-next/285
/dev/loop14                    207232   207232         0 100% /snap/vlc/770
/dev/loop19                     15104    15104         0 100% /snap/gnome-characters/317
/dev/loop16                     99840    99840         0 100% /snap/ubuntu-mate-welcome/296
/dev/loop15                     48896    48896         0 100% /snap/riseup-vpn/152
/dev/loop20                     15104    15104         0 100% /snap/gnome-characters/296
/dev/loop21                    153216   153216         0 100% /snap/slack/16
/dev/loop22                    153600   153600         0 100% /snap/gnome-3-28-1804/71
/dev/loop24                      1280     1280         0 100% /snap/tinc-vpn/2
/dev/loop26                    150144   150144         0 100% /snap/slack/17
/dev/loop27                     43904    43904         0 100% /snap/gtk-common-themes/1313
/dev/loop30                    153600   153600         0 100% /snap/gnome-3-28-1804/67
/dev/loop31                    207744   207744         0 100% /snap/vlc/1049
/dev/loop33                     58368    58368         0 100% /snap/powershell/34
/dev/loop34                     16384    16384         0 100% /snap/communitheme/1768
/dev/loop35                     88832    88832         0 100% /snap/ubuntu-mate-welcome/319
/dev/loop36                    144128   144128         0 100% /snap/gnome-3-26-1604/90
/dev/loop37                    127360   127360         0 100% /snap/electron-mail/13
/dev/loop38                     36224    36224         0 100% /snap/gtk-common-themes/1198
/dev/loop39                    153344   153344         0 100% /snap/chromium/849
/dev/loop40                     77568    77568         0 100% /snap/cubicsdr-casept/4
/dev/loop41                      3840     3840         0 100% /snap/gnome-system-monitor/95
/dev/loop42                     19072    19072         0 100% /snap/communitheme/1524
/dev/loop43                     55808    55808         0 100% /snap/core18/1098
/dev/loop45                    327936   327936         0 100% /snap/pycharm-community/147
/dev/loop46                     69248    69248         0 100% /snap/sublime-text/69
/dev/loop47                      3840     3840         0 100% /snap/gnome-system-monitor/100
/dev/loop48                    224384   224384         0 100% /snap/gimp/189
tmpfs                         1621268       28   1621240   1% /run/user/121
tmpfs                         1621268       76   1621192   1% /run/user/1000
/dev/loop49                    144128   144128         0 100% /snap/gnome-3-26-1604/92
/dev/loop23                     97024    97024         0 100% /snap/telegram-desktop/908
/dev/loop25                     91264    91264         0 100% /snap/core/7713
/dev/loop6                       1024     1024         0 100% /snap/gnome-logs/73
/dev/loop50                      4352     4352         0 100% /snap/gnome-calculator/501
/dev/loop13                     97152    97152         0 100% /snap/telegram-desktop/936
/dev/loop17                    268544   268544         0 100% /snap/gnss-sdr-next/292
/dev/loop0                     159616   159616         0 100% /snap/chromium/853
/dev/loop18                    327936   327936         0 100% /snap/pycharm-community/150
/dev/loop28                     55808    55808         0 100% /snap/core18/1144
(base) x@x:~$ 

Hardware List:

root@x:/home/x# lshw
x                           
    description: Notebook
    product: 80RU (LENOVO_MT_80RU_BU_idea_FM_Lenovo ideapad 700-15ISK)
    vendor: LENOVO
    version: Lenovo ideapad 700-15ISK
    serial: R90K3F7XR9N0B631000C
    width: 64 bits
    capabilities: smbios-2.8 dmi-2.8 smp vsyscall32
    configuration: administrator_password=enabled boot=normal chassis=notebook family=IDEAPAD frontpanel_password=disabled keyboard_password=disabled power-on_password=disabled sku=LENOVO_MT_80RU_BU_idea_FM_Lenovo ideapad 700-15ISK uuid=800CF8AE-A5E6-E511-88B2-08D40CB5171E
  *-core
       description: Motherboard
       product: Lenovo ideapad 700-15ISK
       vendor: LENOVO
       physical id: 0
       version: SDK0J40709 WIN
       serial: R90K3F7X
       slot: Part Component
     *-cache:0
          description: L1 cache
          physical id: 2
          slot: L1 Cache
          size: 128KiB
          capacity: 128KiB
          capabilities: synchronous internal write-back data
          configuration: level=1
     *-cache:1
          description: L1 cache
          physical id: 3
          slot: L1 Cache
          size: 128KiB
          capacity: 128KiB
          capabilities: synchronous internal write-back instruction
          configuration: level=1
     *-cache:2
          description: L2 cache
          physical id: 4
          slot: L2 Cache
          size: 1MiB
          capacity: 1MiB
          capabilities: synchronous internal write-back unified
          configuration: level=2
     *-cache:3
          description: L3 cache
          physical id: 5
          slot: L3 Cache
          size: 6MiB
          capacity: 6MiB
          capabilities: synchronous internal write-back unified
          configuration: level=3
     *-cpu
          description: CPU
          product: Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz
          vendor: Intel Corp.
          physical id: 6
          bus info: cpu@0
          version: Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz
          serial: To Be Filled By O.E.M.
          slot: U3E1
          size: 2349MHz
          capacity: 3500MHz
          width: 64 bits
          clock: 100MHz
          capabilities: x86-64 fpu fpu_exception wp vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx pdpe1gb rdtscp constant_tsc art arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc cpuid aperfmperf tsc_known_freq pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 sdbg fma cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm 3dnowprefetch cpuid_fault epb invpcid_single pti ssbd ibrs ibpb stibp tpr_shadow vnmi flexpriority ept vpid fsgsbase tsc_adjust bmi1 hle avx2 smep bmi2 erms invpcid rtm mpx rdseed adx smap clflushopt intel_pt xsaveopt xsavec xgetbv1 xsaves dtherm ida arat pln pts hwp hwp_notify hwp_act_window hwp_epp md_clear flush_l1d cpufreq
          configuration: cores=4 enabledcores=4 threads=8
     *-memory
          description: System Memory
          physical id: 7
          slot: System board or motherboard
          size: 16GiB
        *-bank:0
             description: SODIMM DDR4 Synchronous 2133 MHz (0.5 ns)
             product: CT8G4SFD8213.C16FBD1
             vendor: Conexant (Rockwell)
             physical id: 0
             serial: 16141922
             slot: ChannelA-DIMM0
             size: 8GiB
             width: 64 bits
             clock: 2133MHz (0.5ns)
        *-bank:1
             description: Project-Id-Version: lshwReport-Msgid-Bugs-To: FULL NAME PO-Revision-Date: 2012-02-05 00:26+0000Last-Translator: Andi Chandler Language-Team: English (United Kingdom) MIME-Version: 1.0Content-Type: text/plain; charset=UTF-8Content-Transfer-Encoding: 8bitX-Launchpad-Export-Date: 2018-07-12 13:19+0000X-Generator: Launchpad (build 18719)Project-Id-Version: lshwReport-Msgid-Bugs-To: FULL NAME PO-Revision-Date: 2012-02-05 00:26+0000Last-Translator: Andi Chandler Language-Team: English (United Kingdom) MIME-Version: 1.0Content-Type: text/plain; charset=UTF-8Content-Transfer-Encoding: 8bitX-Launchpad-Export-Date: 2018-07-12 13:19+0000X-Generator: Launchpad (build 18719) (empty)
             physical id: 1
             slot: ChannelA-DIMM1
        *-bank:2
             description: SODIMM DDR4 Synchronous 2133 MHz (0.5 ns)
             product: CT8G4SFD8213.C16FBD1
             vendor: Conexant (Rockwell)
             physical id: 2
             serial: 16270421
             slot: ChannelB-DIMM0
             size: 8GiB
             width: 64 bits
             clock: 2133MHz (0.5ns)
        *-bank:3
             description: Project-Id-Version: lshwReport-Msgid-Bugs-To: FULL NAME PO-Revision-Date: 2012-02-05 00:26+0000Last-Translator: Andi Chandler Language-Team: English (United Kingdom) MIME-Version: 1.0Content-Type: text/plain; charset=UTF-8Content-Transfer-Encoding: 8bitX-Launchpad-Export-Date: 2018-07-12 13:19+0000X-Generator: Launchpad (build 18719)Project-Id-Version: lshwReport-Msgid-Bugs-To: FULL NAME PO-Revision-Date: 2012-02-05 00:26+0000Last-Translator: Andi Chandler Language-Team: English (United Kingdom) MIME-Version: 1.0Content-Type: text/plain; charset=UTF-8Content-Transfer-Encoding: 8bitX-Launchpad-Export-Date: 2018-07-12 13:19+0000X-Generator: Launchpad (build 18719) (empty)
             physical id: 3
             slot: ChannelB-DIMM1
     *-firmware
          description: BIOS
          vendor: LENOVO
          physical id: d
          version: E5CN21WW
          date: 12/28/2015
          size: 128KiB
          capacity: 8128KiB
          capabilities: pci upgrade shadowing cdboot bootselect edd int5printscreen int9keyboard int14serial int17printer int10video pc98 acpi usb ls120boot zipboot biosbootspecification netboot
     *-pci
          description: Host bridge
          product: Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor Host Bridge/DRAM Registers
          vendor: Intel Corporation
          physical id: 100
          bus info: pci@0000:00:00.0
          version: 07
          width: 32 bits
          clock: 33MHz
          configuration: driver=skl_uncore
          resources: irq:0
        *-pci:0
             description: PCI bridge
             product: Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor PCIe Controller (x16)
             vendor: Intel Corporation
             physical id: 1
             bus info: pci@0000:00:01.0
             version: 07
             width: 32 bits
             clock: 33MHz
             capabilities: pci pm msi pciexpress normal_decode bus_master cap_list
             configuration: driver=pcieport
             resources: irq:120 ioport:d000(size=4096) memory:d1000000-d1ffffff ioport:a0000000(size=301989888)
           *-display
                description: 3D controller
                product: GM107M (GeForce GTX 950M)
                vendor: NVIDIA Corporation
                physical id: 0
                bus info: pci@0000:01:00.0
                version: a2
                width: 64 bits
                clock: 33MHz
                capabilities: pm msi pciexpress bus_master cap_list
                configuration: driver=nouveau latency=0
                resources: irq:126 memory:d1000000-d1ffffff memory:a0000000-afffffff memory:b0000000-b1ffffff ioport:d000(size=128)
        *-display
             description: VGA compatible controller
             product: HD Graphics 530
             vendor: Intel Corporation
             physical id: 2
             bus info: pci@0000:00:02.0
             version: 06
             width: 64 bits
             clock: 33MHz
             capabilities: pciexpress msi pm vga_controller bus_master cap_list rom
             configuration: driver=i915 latency=0
             resources: irq:127 memory:d0000000-d0ffffff memory:c0000000-cfffffff ioport:e000(size=64) memory:c0000-dffff
        *-usb
             description: USB controller
             product: 100 Series/C230 Series Chipset Family USB 3.0 xHCI Controller
             vendor: Intel Corporation
             physical id: 14
             bus info: pci@0000:00:14.0
             version: 31
             width: 64 bits
             clock: 33MHz
             capabilities: pm msi xhci bus_master cap_list
             configuration: driver=xhci_hcd latency=0
             resources: irq:123 memory:d2200000-d220ffff
           *-usbhost:0
                product: xHCI Host Controller
                vendor: Linux 4.15.0-60-generic xhci-hcd
                physical id: 0
                bus info: usb@1
                logical name: usb1
                version: 4.15
                capabilities: usb-2.00
                configuration: driver=hub slots=16 speed=480Mbit/s
              *-usb:0
                   description: Keyboard
                   product: USB Receiver
                   vendor: Logitech
                   physical id: 1
                   bus info: usb@1:1
                   version: 29.01
                   capabilities: usb-2.00
                   configuration: driver=usbhid maxpower=98mA speed=12Mbit/s
              *-usb:1
                   description: Video
                   product: Lenovo EasyCamera
                   vendor: Bison
                   physical id: 5
                   bus info: usb@1:5
                   version: 42.09
                   serial: 200901010001
                   capabilities: usb-2.00
                   configuration: driver=uvcvideo maxpower=500mA speed=480Mbit/s
              *-usb:2
                   description: Bluetooth wireless interface
                   vendor: Intel Corp.
                   physical id: 7
                   bus info: usb@1:7
                   version: 0.01
                   capabilities: bluetooth usb-2.00
                   configuration: driver=btusb maxpower=100mA speed=12Mbit/s
           *-usbhost:1
                product: xHCI Host Controller
                vendor: Linux 4.15.0-60-generic xhci-hcd
                physical id: 1
                bus info: usb@2
                logical name: usb2
                version: 4.15
                capabilities: usb-3.00
                configuration: driver=hub slots=8 speed=5000Mbit/s
        *-generic:0
             description: Signal processing controller
             product: 100 Series/C230 Series Chipset Family Thermal Subsystem
             vendor: Intel Corporation
             physical id: 14.2
             bus info: pci@0000:00:14.2
             version: 31
             width: 64 bits
             clock: 33MHz
             capabilities: pm msi bus_master cap_list
             configuration: driver=intel_pch_thermal latency=0
             resources: irq:18 memory:d222a000-d222afff
        *-communication
             description: Communication controller
             product: 100 Series/C230 Series Chipset Family MEI Controller #1
             vendor: Intel Corporation
             physical id: 16
             bus info: pci@0000:00:16.0
             version: 31
             width: 64 bits
             clock: 33MHz
             capabilities: pm msi bus_master cap_list
             configuration: driver=mei_me latency=0
             resources: irq:128 memory:d222c000-d222cfff
        *-storage
             description: SATA controller
             product: HM170/QM170 Chipset SATA Controller (AHCI Mode)
             vendor: Intel Corporation
             physical id: 17
             bus info: pci@0000:00:17.0
             version: 31
             width: 32 bits
             clock: 66MHz
             capabilities: storage msi pm ahci_1.0 bus_master cap_list
             configuration: driver=ahci latency=0
             resources: irq:124 memory:d2228000-d2229fff memory:d2230000-d22300ff ioport:e080(size=8) ioport:e088(size=4) ioport:e060(size=32) memory:d222e000-d222e7ff
        *-pci:1
             description: PCI bridge
             product: 100 Series/C230 Series Chipset Family PCI Express Root Port #5
             vendor: Intel Corporation
             physical id: 1c
             bus info: pci@0000:00:1c.0
             version: f1
             width: 32 bits
             clock: 33MHz
             capabilities: pci pciexpress msi pm normal_decode bus_master cap_list
             configuration: driver=pcieport
             resources: irq:121 memory:d2100000-d21fffff
           *-network
                description: Wireless interface
                product: Dual Band Wireless-AC 3165 Plus Bluetooth
                vendor: Intel Corporation
                physical id: 0
                bus info: pci@0000:02:00.0
                logical name: wlp2s0
                version: 99
                serial: 08:d4:0c:b5:17:1a
                width: 64 bits
                clock: 33MHz
                capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
                configuration: broadcast=yes driver=iwlwifi driverversion=4.15.0-60-generic firmware=29.1044073957.0 ip=192.168.1.69 latency=0 link=yes multicast=yes wireless=IEEE 802.11
                resources: irq:129 memory:d2100000-d2101fff
        *-pci:2
             description: PCI bridge
             product: 100 Series/C230 Series Chipset Family PCI Express Root Port #6
             vendor: Intel Corporation
             physical id: 1c.5
             bus info: pci@0000:00:1c.5
             version: f1
             width: 32 bits
             clock: 33MHz
             capabilities: pci pciexpress msi pm normal_decode bus_master cap_list
             configuration: driver=pcieport
             resources: irq:122 ioport:c000(size=4096) memory:d2000000-d20fffff
           *-network
                description: Ethernet interface
                product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
                vendor: Realtek Semiconductor Co., Ltd.
                physical id: 0
                bus info: pci@0000:03:00.0
                logical name: enp3s0
                version: 15
                serial: 54:ee:75:94:08:75
                size: 10Mbit/s
                capacity: 1Gbit/s
                width: 64 bits
                clock: 33MHz
                capabilities: pm msi pciexpress msix bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
                configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half firmware=rtl8168h-2_0.0.2 02/26/15 latency=0 link=no multicast=yes port=MII speed=10Mbit/s
                resources: irq:17 ioport:c000(size=256) memory:d2004000-d2004fff memory:d2000000-d2003fff
        *-generic:1
             description: Signal processing controller
             product: 100 Series/C230 Series Chipset Family Serial IO UART #0
             vendor: Intel Corporation
             physical id: 1e
             bus info: pci@0000:00:1e.0
             version: 31
             width: 64 bits
             clock: 33MHz
             capabilities: pm bus_master cap_list
             configuration: driver=intel-lpss latency=0
             resources: irq:20 memory:d222d000-d222dfff
        *-isa
             description: ISA bridge
             product: HM170 Chipset LPC/eSPI Controller
             vendor: Intel Corporation
             physical id: 1f
             bus info: pci@0000:00:1f.0
             version: 31
             width: 32 bits
             clock: 33MHz
             capabilities: isa bus_master
             configuration: latency=0
        *-memory UNCLAIMED
             description: Memory controller
             product: 100 Series/C230 Series Chipset Family Power Management Controller
             vendor: Intel Corporation
             physical id: 1f.2
             bus info: pci@0000:00:1f.2
             version: 31
             width: 32 bits
             clock: 33MHz (30.3ns)
             capabilities: bus_master
             configuration: latency=0
             resources: memory:d2224000-d2227fff
        *-multimedia
             description: Audio device
             product: 100 Series/C230 Series Chipset Family HD Audio Controller
             vendor: Intel Corporation
             physical id: 1f.3
             bus info: pci@0000:00:1f.3
             version: 31
             width: 64 bits
             clock: 33MHz
             capabilities: pm msi bus_master cap_list
             configuration: driver=snd_hda_intel latency=64
             resources: irq:130 memory:d2220000-d2223fff memory:d2210000-d221ffff
        *-serial UNCLAIMED
             description: SMBus
             product: 100 Series/C230 Series Chipset Family SMBus
             vendor: Intel Corporation
             physical id: 1f.4
             bus info: pci@0000:00:1f.4
             version: 31
             width: 64 bits
             clock: 33MHz
             configuration: latency=0
             resources: memory:d222f000-d222f0ff ioport:efa0(size=32)
     *-scsi:0
          physical id: 0
          logical name: scsi0
          capabilities: emulated
        *-disk
             description: ATA Disk
             product: ADATA SP550NS38
             physical id: 0.0.0
             bus info: scsi@0:0.0.0
             logical name: /dev/sda
             version: 4B
             serial: 2G4220000183
             size: 111GiB (120GB)
             capabilities: partitioned partitioned:dos
             configuration: ansiversion=5 logicalsectorsize=512 sectorsize=512 signature=cb312d6a
           *-volume:0
                description: EXT4 volume
                vendor: Linux
                physical id: 1
                bus info: scsi@0:0.0.0,1
                logical name: /dev/sda1
                logical name: /boot
                version: 1.0
                serial: 6480205e-88e0-4b20-b930-38dee5b56148
                size: 731MiB
                capacity: 731MiB
                capabilities: primary bootable journaled extended_attributes large_files huge_files dir_nlink recover 64bit extents ext4 ext2 initialized
                configuration: created=2018-11-11 23:13:29 filesystem=ext4 lastmountpoint=/boot modified=2019-09-08 17:24:42 mount.fstype=ext4 mount.options=rw,relatime,data=ordered mounted=2019-09-08 17:24:42 state=mounted
           *-volume:1
                description: Extended partition
                physical id: 2
                bus info: scsi@0:0.0.0,2
                logical name: /dev/sda2
                size: 111GiB
                capacity: 111GiB
                capabilities: primary extended partitioned partitioned:extended
              *-logicalvolume
                   description: Linux filesystem partition
                   physical id: 5
                   logical name: /dev/sda5
                   serial: 775a1793-1ea1-4fe2-bcd9-4880a3924ee0
                   size: 111GiB
                   capacity: 111GiB
                   width: 512 bits
                   capabilities: encrypted luks initialized
                   configuration: bits=512 cipher=aes filesystem=luks hash=sha256 mode=xts-plain64 version=1
     *-scsi:1
          physical id: 1
          logical name: scsi2
          capabilities: emulated
        *-disk
             description: ATA Disk
             product: WDC WD10SPCX-24H
             vendor: Western Digital
             physical id: 0.0.0
             bus info: scsi@2:0.0.0
             logical name: /dev/sdb
             version: 1A02
             serial: WD-WXA1AB57JSDL
             size: 931GiB (1TB)
             capabilities: partitioned partitioned:dos
             configuration: ansiversion=5 logicalsectorsize=512 sectorsize=4096 signature=30d5ab25
           *-volume
                description: EXT4 volume
                vendor: Linux
                physical id: 1
                bus info: scsi@2:0.0.0,1
                logical name: /dev/sdb1
                version: 1.0
                serial: 0210a406-4dce-4a43-ac18-82f1a30c8c2c
                size: 931GiB
                capacity: 931GiB
                capabilities: primary journaled extended_attributes large_files huge_files dir_nlink 64bit extents ext4 ext2 initialized
                configuration: created=2018-11-09 17:40:00 filesystem=ext4 label=1TB lastmountpoint=/media/x/1TB modified=2019-09-06 11:31:08 mounted=2019-09-06 11:31:04 state=clean
  *-battery
       product: Smart Battery
       vendor: Intel Corp.
       physical id: 1
       version: 2008
       serial: 1.0
       slot: Rear