我有一个 USB 闪存但无法写入它所以我尝试这指令并得到以下输出：
root@so-notebook:~# df -Th
Filesystem Type Size Used Avail Use% Mounted on
udev devtmpfs 5.8G 0 5.8G 0% /dev
tmpfs tmpfs 1.2G 4.4M 1.2G 1% /run
/dev/sda4 ext4 91G 60G 27G 70% /
tmpfs tmpfs 5.9G 162M 5.7G 3% /dev/shm
tmpfs tmpfs 5.0M 4.0K 5.0M 1% /run/lock
tmpfs tmpfs 5.9G 0 5.9G 0% /sys/fs/cgroup
/dev/loop1 squashfs 27M 27M 0 100% /snap/sickgear/844
/dev/loop2 squashfs 145M 145M 0 100% /snap/code/36
/dev/loop3 squashfs 55M 55M 0 100% /snap/core18/1754
/dev/loop0 squashfs 141M 141M 0 100% /snap/opera/80
/dev/loop4 squashfs 9.7M 9.7M 0 100% /snap/ktorrent/9
/dev/loop5 squashfs 30M 30M 0 100% /snap/node/2847
/dev/loop6 squashfs 1.0M 1.0M 0 100% /snap/gnome-logs/100
/dev/loop7 squashfs 179M 179M 0 100% /snap/arduino-mhall119/7
/dev/loop9 squashfs 129M 129M 0 100% /snap/deepin-voice-recorder/1
/dev/loop8 squashfs 290M 290M 0 100% /snap/kde-frameworks-5-qt-5-14-core18/3
/dev/loop10 squashfs 60M 60M 0 100% /snap/mockuuups/3
/dev/loop11 squashfs 61M 61M 0 100% /snap/zenkit-todo/5
/dev/loop12 squashfs 341M 341M 0 100% /snap/pycharm-community/202
/dev/loop13 squashfs 110M 110M 0 100% /snap/openscad-nightly/1842
/dev/loop14 squashfs 6.8M 6.8M 0 100% /snap/wireguard-ammp/95
/dev/loop15 squashfs 140M 140M 0 100% /snap/slack/24
/dev/loop17 squashfs 384K 384K 0 100% /snap/uboot-tools/3
/dev/loop18 squashfs 340M 340M 0 100% /snap/pycharm-community/197
/dev/loop16 squashfs 9.7M 9.7M 0 100% /snap/ktorrent/7
/dev/loop19 squashfs 142M 142M 0 100% /snap/inkscape/7601
/dev/loop20 squashfs 4.7M 4.7M 0 100% /snap/spreedme/22
/dev/loop21 squashfs 4.2M 4.2M 0 100% /snap/notepad-plus-plus/234
/dev/loop23 squashfs 161M 161M 0 100% /snap/opentoonz-morevna/72
/dev/loop24 squashfs 163M 163M 0 100% /snap/blender/40
/dev/loop22 squashfs 33M 33M 0 100% /snap/domotzpro-agent-publicstore/66
/dev/loop26 squashfs 8.0M 8.0M 0 100% /snap/pulsemixer/283
/dev/loop25 squashfs 26M 26M 0 100% /snap/heroku/3960
/dev/loop27 squashfs 115M 115M 0 100% /snap/signal-desktop/325
/dev/loop28 squashfs 708M 708M 0 100% /snap/android-studio/88
/dev/loop29 squashfs 230M 230M 0 100% /snap/qt513/18
/dev/loop30 squashfs 2.3M 2.3M 0 100% /snap/red-app/18
/dev/loop31 squashfs 64M 64M 0 100% /snap/vrew/138
/dev/loop32 squashfs 58M 58M 0 100% /snap/jdownloader2/10
/dev/loop33 squashfs 63M 63M 0 100% /snap/gtk-common-themes/1506
/dev/loop37 squashfs 118M 118M 0 100% /snap/google-cloud-sdk/140
/dev/loop36 squashfs 29M 29M 0 100% /snap/chromium-ffmpeg/15
/dev/loop35 squashfs 106M 106M 0 100% /snap/deja-dup/350
/dev/loop39 squashfs 109M 109M 0 100% /snap/odrive-unofficial/2
/dev/loop34 squashfs 160M 160M 0 100% /snap/polar-bookshelf/85
/dev/loop38 squashfs 256M 256M 0 100% /snap/gnome-3-34-1804/36
/dev/loop42 squashfs 163M 163M 0 100% /snap/blender/41
/dev/loop43 squashfs 74M 74M 0 100% /snap/poddr/5
/dev/loop40 squashfs 188M 188M 0 100% /snap/clementine/659
/dev/loop41 squashfs 254M 254M 0 100% /snap/subsync/9
/dev/loop44 squashfs 227M 227M 0 100% /snap/wine-platform-runtime/136
/dev/loop45 squashfs 128K 128K 0 100% /snap/acrordrdc/8
/dev/loop46 squashfs 173M 173M 0 100% /snap/qt551/30
/dev/loop47 squashfs 8.7M 8.7M 0 100% /snap/nmap/823
/dev/loop49 squashfs 62M 62M 0 100% /snap/rocketchat-desktop/156
/dev/loop48 squashfs 107M 107M 0 100% /snap/yakyak/74
/dev/loop50 squashfs 185M 185M 0 100% /snap/eclipse/40
/dev/loop51 squashfs 141M 141M 0 100% /snap/opera/81
/dev/loop52 squashfs 30M 30M 0 100% /snap/node/2853
/dev/loop53 squashfs 2.5M 2.5M 0 100% /snap/gnome-calculator/730
/dev/loop54 squashfs 98M 98M 0 100% /snap/core/9289
/dev/loop56 squashfs 61M 61M 0 100% /snap/core20/634
/dev/loop55 squashfs 160M 160M 0 100% /snap/opentoonz/84
/dev/loop57 squashfs 54M 54M 0 100% /snap/telemetrytv/28
/dev/loop58 squashfs 2.5M 2.5M 0 100% /snap/gnome-calculator/748
/dev/loop59 squashfs 72M 72M 0 100% /snap/insomnia/69
/dev/loop60 squashfs 2.2M 2.2M 0 100% /snap/mosquitto/269
/dev/loop61 squashfs 152M 152M 0 100% /snap/arduino-mhall119/5
/dev/loop62 squashfs 20M 20M 0 100% /snap/okular/98
/dev/loop63 squashfs 164M 164M 0 100% /snap/postman/116
/dev/loop64 squashfs 2.9M 2.9M 0 100% /snap/utube/45
/dev/loop65 squashfs 2.2M 2.2M 0 100% /snap/mosquitto/298
/dev/loop67 squashfs 110M 110M 0 100% /snap/transitionsdj/13
/dev/loop70 squashfs 256K 256K 0 100% /snap/gtk2-common-themes/13
/dev/loop66 squashfs 118M 118M 0 100% /snap/google-cloud-sdk/139
/dev/loop71 squashfs 162M 162M 0 100% /snap/gnome-3-28-1804/128
/dev/loop69 squashfs 141M 141M 0 100% /snap/mathpix-snipping-tool/104
/dev/loop68 squashfs 8.0M 8.0M 0 100% /snap/pulsemixer/250
/dev/loop72 squashfs 74M 74M 0 100% /snap/alexaweb/1
/dev/loop73 squashfs 87M 87M 0 100% /snap/shotcut/67
/dev/loop74 squashfs 87M 87M 0 100% /snap/shotcut/64
/dev/loop76 squashfs 129M 129M 0 100% /snap/meshlab/5
/dev/loop77 squashfs 63M 63M 0 100% /snap/telegram-desktop/1671
/dev/loop75 squashfs 74M 74M 0 100% /snap/wine-platform-3-stable/6
/dev/loop78 squashfs 1.4M 1.4M 0 100% /snap/anifx/21
/dev/loop79 squashfs 254M 254M 0 100% /snap/subsync/10
/dev/loop80 squashfs 64M 64M 0 100% /snap/vrew/139
/dev/loop82 squashfs 2.8M 2.8M 0 100% /snap/telegram-cli/25
/dev/loop81 squashfs 291M 291M 0 100% /snap/vlc/1620
/dev/loop83 squashfs 12M 12M 0 100% /snap/hangups/142
/dev/loop85 squashfs 55M 55M 0 100% /snap/core18/1705
/dev/loop84 squashfs 59M 59M 0 100% /snap/kesty-whatsapp/35
/dev/loop89 squashfs 14M 14M 0 100% /snap/tor-middle-relay/277
/dev/loop88 squashfs 230M 230M 0 100% /snap/qt513/19
/dev/loop87 squashfs 33M 33M 0 100% /snap/node-red/590
/dev/loop91 squashfs 142M 142M 0 100% /snap/inkscape/7627
/dev/loop90 squashfs 384K 384K 0 100% /snap/gnome-characters/550
/dev/loop86 squashfs 1.8G 1.8G 0 100% /snap/webots/14
/dev/loop92 squashfs 2.3M 2.3M 0 100% /snap/red-app/19
/dev/loop96 squashfs 5.2M 5.2M 0 100% /snap/rclone-dev/16
/dev/loop95 squashfs 61M 61M 0 100% /snap/translatium/63
/dev/loop94 squashfs 233M 233M 0 100% /snap/nextcloud/20498
/dev/loop93 squashfs 102M 102M 0 100% /snap/p7zip-desktop/220
/dev/loop98 squashfs 173M 173M 0 100% /snap/qt551/29
/dev/loop97 squashfs 33M 33M 0 100% /snap/domotzpro-agent-publicstore/69
/dev/loop101 squashfs 4.0M 4.0M 0 100% /snap/notepad-plus-plus/232
/dev/loop99 squashfs 19M 19M 0 100% /snap/ike-qt/7
/dev/loop100 squashfs 227M 227M 0 100% /snap/wine-platform-runtime/145
/dev/loop102 squashfs 95M 95M 0 100% /snap/google-play-music-desktop-player/80
/dev/loop106 squashfs 61M 61M 0 100% /snap/mockuuups/5
/dev/loop104 squashfs 83M 83M 0 100% /snap/ultimate-media-downloader/3
/dev/loop105 squashfs 215M 215M 0 100% /snap/wine-platform-5-stable/4
/dev/loop107 squashfs 45M 45M 0 100% /snap/filezilla/17
/dev/loop103 squashfs 139M 139M 0 100% /snap/kdictionary/2
/dev/loop109 squashfs 145M 145M 0 100% /snap/code/35
/dev/loop110 squashfs 4.5M 4.5M 0 100% /snap/ormesh/12
/dev/loop108 squashfs 134M 134M 0 100% /snap/projectlibre/3
/dev/loop111 squashfs 8.7M 8.7M 0 100% /snap/nmap/1356
/dev/loop112 squashfs 236M 236M 0 100% /snap/kde-frameworks-5/27
/dev/loop113 squashfs 54M 54M 0 100% /snap/telemetrytv/27
/dev/loop117 squashfs 1.0M 1.0M 0 100% /snap/gnome-logs/93
/dev/loop116 squashfs 62M 62M 0 100% /snap/rocketchat-desktop/157
/dev/loop114 squashfs 55M 55M 0 100% /snap/gtk-common-themes/1502
/dev/loop115 squashfs 44M 44M 0 100% /snap/riseup-vpn/159
/dev/loop119 squashfs 211M 211M 0 100% /snap/eclipse/48
/dev/loop121 squashfs 261M 261M 0 100% /snap/kde-frameworks-5-core18/32
/dev/loop118 squashfs 68M 68M 0 100% /snap/superproductivity/673
/dev/loop123 squashfs 204M 204M 0 100% /snap/cloudcompare/205
/dev/loop122 squashfs 279M 279M 0 100% /snap/octave/30
/dev/loop120 squashfs 801M 801M 0 100% /snap/android-studio/90
/dev/loop124 squashfs 110M 110M 0 100% /snap/odio/5
/dev/loop125 squashfs 164M 164M 0 100% /snap/postman/115
/dev/loop126 squashfs 61M 61M 0 100% /snap/translatium/62
/dev/loop127 squashfs 59M 59M 0 100% /snap/kesty-whatsapp/37
/dev/loop129 squashfs 384K 384K 0 100% /snap/micropython/80
/dev/loop128 squashfs 256M 256M 0 100% /snap/gnome-3-34-1804/33
/dev/loop131 squashfs 215M 215M 0 100% /snap/wine-platform-5-stable/5
/dev/loop130 squashfs 5.9M 5.9M 0 100% /snap/tor/2
/dev/loop135 squashfs 41M 41M 0 100% /snap/telegram-testbart/3
/dev/loop132 squashfs 188M 188M 0 100% /snap/arduino/32
/dev/loop141 squashfs 1.9M 1.9M 0 100% /snap/uconfig/118
/dev/loop142 squashfs 77M 77M 0 100% /snap/insomnia/74
/dev/loop134 squashfs 68M 68M 0 100% /snap/superproductivity/686
/dev/loop146 squashfs 20M 20M 0 100% /snap/okular/90
/dev/loop133 squashfs 160M 160M 0 100% /snap/opentoonz/94
/dev/loop152 squashfs 27M 27M 0 100% /snap/minuet/49
/dev/loop138 squashfs 60M 60M 0 100% /snap/youtubeport/5
/dev/loop150 squashfs 2.3M 2.3M 0 100% /snap/gnome-system-monitor/145
/dev/loop144 squashfs 384K 384K 0 100% /snap/gnome-characters/539
/dev/loop153 squashfs 161M 161M 0 100% /snap/opentoonz-morevna/77
/dev/loop136 squashfs 61M 61M 0 100% /snap/mtpaint-casept/1
/dev/loop157 squashfs 2.9M 2.9M 0 100% /snap/utube/46
/dev/loop154 squashfs 2.3M 2.3M 0 100% /snap/gnome-system-monitor/148
/dev/loop143 squashfs 165M 165M 0 100% /snap/polar-bookshelf/86
/dev/loop158 squashfs 144M 144M 0 100% /snap/gydl/2
/dev/loop148 squashfs 97M 97M 0 100% /snap/core/9436
/dev/loop140 squashfs 98M 98M 0 100% /snap/uconfig/112
/dev/loop156 squashfs 141M 141M 0 100% /snap/mathpix-snipping-tool/155
/dev/loop166 squashfs 374M 374M 0 100% /snap/anbox/186
/dev/loop164 squashfs 124M 124M 0 100% /snap/krita/55
/dev/loop162 squashfs 161M 161M 0 100% /snap/gnome-3-28-1804/116
/dev/loop147 squashfs 136M 136M 0 100% /snap/cloudcompare/200
/dev/loop139 squashfs 27M 27M 0 100% /snap/sickgear/850
/dev/loop170 squashfs 114M 114M 0 100% /snap/audacity/666
/dev/loop151 squashfs 142M 142M 0 100% /snap/arduino/41
/dev/loop174 squashfs 44M 44M 0 100% /snap/riseup-vpn/161
/dev/loop167 squashfs 400M 400M 0 100% /snap/mycroft/463
/dev/loop168 squashfs 126M 126M 0 100% /snap/krita/57
/dev/loop180 squashfs 8.5M 8.5M 0 100% /snap/sprinkle/2
/dev/loop137 squashfs 103M 103M 0 100% /snap/deja-dup/344
/dev/loop161 squashfs 115M 115M 0 100% /snap/signal-desktop/324
/dev/loop159 squashfs 2.0M 2.0M 0 100% /snap/fast/4
/dev/loop145 squashfs 33M 33M 0 100% /snap/node-red/595
/dev/loop160 squashfs 96M 96M 0 100% /snap/yakyak/70
/dev/loop155 squashfs 26M 26M 0 100% /snap/heroku/3947
/dev/loop185 squashfs 58M 58M 0 100% /snap/jdownloader2/9
/dev/loop163 squashfs 110M 110M 0 100% /snap/openscad-nightly/1851
/dev/loop184 squashfs 291M 291M 0 100% /snap/vlc/1700
/dev/loop169 squashfs 16M 16M 0 100% /snap/telega/24
/dev/loop179 squashfs 6.0M 6.0M 0 100% /snap/wireguard-ammp/72
/dev/loop172 squashfs 152M 152M 0 100% /snap/telegram-desktop/1708
/dev/loop149 squashfs 88M 88M 0 100% /snap/meshlab-mardy/5
/dev/loop181 squashfs 219M 219M 0 100% /snap/nextcloud/20007
/dev/loop165 squashfs 195M 195M 0 100% /snap/clementine/890
/dev/loop171 squashfs 256K 256K 0 100% /snap/gtk2-common-themes/9
/dev/loop177 squashfs 131M 131M 0 100% /snap/meshlab/6
/dev/loop173 squashfs 129M 129M 0 100% /snap/deepin-music/1
/dev/loop178 squashfs 276M 276M 0 100% /snap/octave/29
/dev/loop175 squashfs 102M 102M 0 100% /snap/zenkit-todo/3
/dev/loop182 squashfs 114M 114M 0 100% /snap/audacity/675
/dev/loop186 squashfs 145M 145M 0 100% /snap/slack/25
/dev/loop176 squashfs 291M 291M 0 100% /snap/kde-frameworks-5-qt-5-14-core18/4
/dev/loop188 squashfs 1.3M 1.3M 0 100% /snap/tinc-vpn/2
/dev/loop187 squashfs 110M 110M 0 100% /snap/transitionsdj/14
/dev/loop183 squashfs 27M 27M 0 100% /snap/minuet/55
/dev/sda3 ext4 197G 181G 5.8G 97% /home
tmpfs tmpfs 1.2G 48K 1.2G 1% /run/user/1000
/dev/sdb1 vfat 30G 26G 3.8G 88% /media/so/BCC0-8F42
root@so-notebook:~# umount /media/so/BCC0-8F42
root@so-notebook:~# dosfsck -a /dev/sdb1
fsck.fat 4.1 (2017-01-24)
open: Read-only file system
谢谢。