安装过程很顺利。但第一次重启后，发行版无法启动。这就是我在屏幕上看到的全部内容
虚拟盒版本为 4.3.28 r100309（截至撰写本文时为最新版本）
这是 vbox 设置：
$ VBoxManage showvminfo "LinuxDesktop15"
Name: LinuxDesktop15
Groups: /
Guest OS: Ubuntu (64 bit)
UUID: 8bfd870e-f770-429d-bbfc-13b26dffc81d
Config file: /Users/antkong/VirtualBox VMs/LinuxDesktop15/LinuxDesktop15.vbox
Snapshot folder: /Users/antkong/VirtualBox VMs/LinuxDesktop15/Snapshots
Log folder: /Users/antkong/VirtualBox VMs/LinuxDesktop15/Logs
Hardware UUID: 8bfd870e-f770-429d-bbfc-13b26dffc81d
Memory size: 512MB
Page Fusion: off
VRAM size: 16MB
CPU exec cap: 100%
HPET: off
Chipset: piix3
Firmware: BIOS
Number of CPUs: 1
PAE: off
Long Mode: on
Synthetic CPU: off
CPUID overrides: None
Boot menu mode: message and menu
Boot Device (1): Floppy
Boot Device (2): DVD
Boot Device (3): HardDisk
Boot Device (4): Not Assigned
ACPI: on
IOAPIC: on
Time offset: 0ms
RTC: UTC
Hardw. virt.ext: on
Nested Paging: on
Large Pages: on
VT-x VPID: on
VT-x unr. exec.: on
State: running (since 2015-06-16T01:36:17.297000000)
Monitor count: 1
3D Acceleration: off
2D Video Acceleration: off
Teleporter Enabled: off
Teleporter Port: 0
Teleporter Address:
Teleporter Password:
Tracing Enabled: off
Allow Tracing to Access VM: off
Tracing Configuration:
Autostart Enabled: off
Autostart Delay: 0
Default Frontend:
Storage Controller Name (0): IDE
Storage Controller Type (0): PIIX4
Storage Controller Instance Number (0): 0
Storage Controller Max Port Count (0): 2
Storage Controller Port Count (0): 2
Storage Controller Bootable (0): on
Storage Controller Name (1): SATA
Storage Controller Type (1): IntelAhci
Storage Controller Instance Number (1): 0
Storage Controller Max Port Count (1): 30
Storage Controller Port Count (1): 1
Storage Controller Bootable (1): on
IDE (1, 0): /Applications/VirtualBox.app/Contents/MacOS/VBoxGuestAdditions.iso (UUID: 4dbd5fce-db20-4eba-b0ac-e5593aadb08f)
SATA (0, 0): /Users/antkong/VirtualBox VMs/LinuxDesktop15/LinuxDesktop15.vdi (UUID: 5249358d-1608-4f71-851c-5dbd75dd059a)
NIC 1: MAC: 08002708DCB0, Attachment: NAT, Cable connected: on, Trace: off (file: none), Type: 82540EM, Reported speed: 0 Mbps, Boot priority: 0, Promisc Policy: deny, Bandwidth group: none
NIC 1 Settings: MTU: 0, Socket (send: 64, receive: 64), TCP Window (send:64, receive: 64)
NIC 2: disabled
NIC 3: disabled
NIC 4: disabled
NIC 5: disabled
NIC 6: disabled
NIC 7: disabled
NIC 8: disabled
Pointing Device: USB Tablet
Keyboard Device: PS/2 Keyboard
UART 1: disabled
UART 2: disabled
LPT 1: disabled
LPT 2: disabled
Audio: enabled (Driver: CoreAudio, Controller: AC97)
Clipboard Mode: disabled
Drag'n'drop Mode: disabled
Session type: GUI/Qt
Video mode: 720x400x0 at 0,0
VRDE: disabled
USB: enabled
EHCI: enabled
USB Device Filters:
<none>
Available remote USB devices:
<none>
Currently Attached USB Devices:
<none>
Bandwidth groups: <none>
Shared folders: <none>
VRDE Connection: not active
Clients so far: 0
Video capturing: not active
Capture screens: 0
Capture file: /Users/antkong/VirtualBox VMs/LinuxDesktop15/LinuxDesktop15.webm
Capture dimensions: 1024x768
Capture rate: 512 kbps
Capture FPS: 25
Guest:
Configured memory balloon size: 0 MB
OS type: Linux26_64
Additions run level: 1
Additions version: 4.3.22_Ubuntu r98236
Guest Facilities:
Facility "VirtualBox Base Driver": active/running (last update: 2015/06/16 01:36:42 UTC)
Facility "Seamless Mode": not active (last update: 2015/06/16 01:36:42 UTC)
Facility "Graphics Mode": not active (last update: 2015/06/16 01:36:42 UTC)
问题是什么？
答案1
你的屏幕上清楚地显示：
blk_update_request: I/O error, dev sr0, sector....
这设备 sr0在 Linux 中，是 CD/DVD 读取器。这意味着您的 VM 尝试读取 squashfs 的不是硬盘（它可能驻留在硬盘上），而是 CD/DVD 磁盘（这可能是您在安装期间设置的）。
您应该更改启动顺序，使 HDD 优先于其他任何设备。但您还应该确保 HDD 存在，并且可启动，因为标准程序是，如果未找到 CD/DVD，则启动过程应毫不犹豫地转到 HDD，而事实并非如此，这让我怀疑 HDD 不存在或不可启动。
无论如何，您可以使用安装介质（USB 或 CD/DVD）执行任一操作：从中启动，然后选择：无需安装即可试用 Ubuntu。