我最近买了一台新的戴尔笔记本电脑，我想在上面启动 Ubuntu。目前我可以通过插入 USB 来启动它，但是当我尝试安装时，我收到错误：You need at least 8.6 GB disk space to install Ubuntu. This computer has only 8.0 GB.
如何释放磁盘空间？我也不想要双启动，我可以删除 Windows 操作系统，只使用 Ubuntu。
这是我运行时的输出df -h。
Filesystem Size Used Avail Use% Mounted on
udev 7.7G 0 7.7G 0% /dev
tmpfs 1.6G 1.8M 1.6G 1% /run
/dev/sda 1.9G 1.9G 0 100% /cdrom
/dev/loop0 1.8G 1.8G 0 100% /rofs
/cow 7.7G 425M 7.3G 6% /
tmpfs 7.7G 49M 7.7G 1% /dev/shm
tmpfs 5.0M 8.0K 5.0M 1% /run/lock
tmpfs 7.7G 0 7.7G 0% /sys/fs/cgroup
tmpfs 7.7G 516K 7.7G 1% /tmp
tmpfs 1.6G 64K 1.6G 1% /run/user/999
/dev/loop1 91M 91M 0 100% /snap/core/6350
/dev/loop2 35M 35M 0 100% /snap/gtk-common-themes/818
/dev/loop3 141M 141M 0 100% /snap/gnome-3-26-1604/74
/dev/loop4 2.3M 2.3M 0 100% /snap/gnome-calculator/260
/dev/loop5 13M 13M 0 100% /snap/gnome-characters/139
/dev/loop6 15M 15M 0 100% /snap/gnome-logs/45
/dev/loop7 3.8M 3.8M 0 100% /snap/gnome-system-monitor/57
这是我运行时的输出sudo fdist -l：
Disk /dev/loop0: 1.8 GiB, 1905045504 bytes, 3720792 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: 91 MiB, 95408128 bytes, 186344 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: 34.6 MiB, 36216832 bytes, 70736 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: 140.7 MiB, 147496960 bytes, 288080 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: 2.3 MiB, 2355200 bytes, 4600 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: 13 MiB, 13619200 bytes, 26600 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: 14.5 MiB, 15208448 bytes, 29704 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: 3.7 MiB, 3878912 bytes, 7576 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: 7.5 GiB, 8016363520 bytes, 15656960 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: 0x40993ab6
Device Boot Start End Sectors Size Id Type
/dev/sda1 * 0 3899391 3899392 1.9G 0 Empty
/dev/sda2 3830956 3835883 4928 2.4M ef EFI (FAT-12/16/32)
这是戴尔Inspiron 13 7000 二合一。我是新手，所以非常感谢您的帮助！