坦白说，我真的不知道我在这里做什么，我只是真的很讨厌 Windows 10，并试图改用 Ubuntu。如果这个问题已经被问过了，我很抱歉，我已经阅读了许多其他问题，要么无法理解它们，要么甚至无法判断我们的问题是否相同。
我刚买了一台全新的戴尔笔记本电脑，默认操作系统是 Windows 10。我买了一个 SanDisk 64 GB USB 驱动器，并按照HowToGeek 说明用于设置分区并直接从 USB 驱动器启动。我以为我成功了，因为我的电脑现在会自动从 USB 启动并运行 Ubuntu。然而，在运行 Ubuntu 并尝试安装其他程序后，我检查了磁盘空间，它只显示我有 4.1 GB 的空间，只有 136 MB 可用空间。由于 USB 也有 64 GB 的空间，这似乎非常不对，而且我认为对硬盘进行分区的整个目的无论如何都是提供存储空间。这是怎么回事？我该如何解决这个问题？
编辑：这是我运行以下代码时出现的结果：
sudo fdisk -l
Disk /dev/loop0: 1.9 GiB, 1987817472 bytes, 3882456 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/loop1: 88.5 MiB, 92778496 bytes, 181208 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/loop2: 54.4 MiB, 57069568 bytes, 111464 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/loop3: 42.8 MiB, 44879872 bytes, 87656 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/loop4: 149.9 MiB, 157184000 bytes, 307000 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/loop5: 4 MiB, 4218880 bytes, 8240 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/loop6: 14.8 MiB, 15462400 bytes, 30200 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/loop7: 1008 KiB, 1032192 bytes, 2016 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/sda: 57.3 GiB, 61505273856 bytes, 120127488 sectors
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: 0x03510df8
Device Boot Start End Sectors Size Id Type
/dev/sda1 * 2048 120127487 120125440 57.3G c W95 FAT32 (LBA)
Disk /dev/loop8: 3.7 MiB, 3825664 bytes, 7472 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
运行以下代码后：
sudo df -h
Filesystem Size Used Avail Use% Mounted on
udev 3.8G 0 3.8G 0% /dev
tmpfs 775M 1.8M 773M 1% /run
/dev/sda1 58G 2.0G 56G 4% /cdrom
/dev/loop0 1.9G 1.9G 0 100% /rofs
/cow 3.8G 3.7G 130M 97% /
tmpfs 3.8G 204M 3.6G 6% /dev/shm
tmpfs 5.0M 8.0K 5.0M 1% /run/lock
tmpfs 3.8G 0 3.8G 0% /sys/fs/cgroup
tmpfs 3.8G 6.1M 3.8G 1% /tmp
tmpfs 775M 108K 775M 1% /run/user/999
/dev/loop1 89M 89M 0 100% /snap/core/7270
/dev/loop2 55M 55M 0 100% /snap/core18/1066
/dev/loop3 43M 43M 0 100% /snap/gtk-common-themes/1313
/dev/loop4 150M 150M 0 100% /snap/gnome-3-28-1804/67
/dev/loop5 4.2M 4.2M 0 100% /snap/gnome-calculator/406
/dev/loop6 15M 15M 0 100% /snap/gnome-characters/296
/dev/loop7 1.0M 1.0M 0 100% /snap/gnome-logs/61
/dev/loop8 3.8M 3.8M 0 100% /snap/gnome-system-monitor/100
安装 inxi 后：
System: Host: ubuntu Kernel: 5.0.0-23-generic x86_64 bits: 64 gcc: 7.4.0
Desktop: Gnome 3.28.4 (Gtk 3.22.30-1ubuntu4) dm: gdm3
Distro: Ubuntu 18.04.3 LTS
Machine: Device: laptop System: Dell product: Inspiron 5493 serial: N/A
Mobo: Dell model: 0M4FW1 v: A00 serial: N/A
UEFI: Dell v: 1.1.0 date: 08/16/2019
Chassis: type: 10 serial: N/A
Battery BAT0: charge: 39.9 Wh 100.0% condition: 39.9/42.0 Wh (95%)
volts: 13.0/11.4
model: BYD DELL 1VX1H98 serial: <filter>status: Full
CPU: Quad core Intel Core i5-1035G1 (-MT-MCP-)
arch: N/A cache: 6144 KB
flags: (lm nx sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx) bmips: 9523
clock speeds: min/max: 400/3600 MHz 1: 1334 MHz 2: 964 MHz
3: 1152 MHz 4: 863 MHz 5: 938 MHz 6: 1058 MHz 7: 1077 MHz
8: 911 MHz
Graphics: Card: Intel Device 8a56 bus-ID: 00:02.0 chip-ID: 8086:8a56
Display Server: x11 (X.Org 1.20.4 )
drivers: fbdev (unloaded: modesetting,vesa)
Resolution: [email protected]
OpenGL: renderer: llvmpipe (LLVM 8.0, 256 bits)
version: 3.3 Mesa 19.0.8 (compat-v: 3.1) Direct Render: Yes
Audio: Card Intel Device 34c8
driver: snd_hda_intel bus-ID: 00:1f.3 chip-ID: 8086:34c8
Sound: Advanced Linux Sound Architecture v: k5.0.0-23-generic
Network: Card-1: Realtek RTL810xE PCIE Fast Ethernet controller
driver: r8169 port: 3000 bus-ID: 01:00.0 chip-ID: 10ec:8136
IF: enp1s0 state: down mac: <filter>
Card-2: Qualcomm Atheros QCA9377 802.11ac Wireless Network Adapter
driver: ath10k_pci bus-ID: 02:00.0 chip-ID: 168c:0042
IF: wlp2s0 state: up mac: <filter>
Card-3: Atheros usb-ID: 001-005 chip-ID: 0cf3:e009
IF: null-if-id state: N/A speed: N/A duplex: N/A mac: N/A
Drives: HDD Total Size: 61.5GB (3.4% used)
ID-1: USB /dev/sda model: Ultra_Fit size: 61.5GB
serial: <filter> temp: 0C
Partition: ID-1: / size: 3.8G used: 3.7G (97%) fs: overlay dev: N/A
RAID: System: supported: N/A
No RAID devices: /proc/mdstat, md_mod kernel module present
Unused Devices: none
Sensors: System Temperatures: cpu: 62.0C mobo: N/A
Fan Speeds (in rpm): cpu: 2599
Info: Processes: 272 Uptime: 11:00 Memory: 2562.8/7742.7MB
Init: systemd v: 237 runlevel: 5 Gcc sys: N/A
Client: Shell (bash 4.4.201 running in gnome-terminal-) inxi: 2.3.56