Try Ubuntu Before Installing: Test Your Hardware First

A live session is the temporary Ubuntu desktop running from the USB. It is a safe place to ask two questions before installation:

1. Does the everyday hardware work well enough?
2. Can Ubuntu see the internal drive you intend to use?

Most live-session changes disappear after shutdown. That is useful for testing, but it means this session is not your finished system.

Test hardware one item at a time

Failure in one item does not automatically mean Ubuntu can never work. Drivers, firmware updates, or a newer kernel may help. Record the exact device model and symptom. A missing internal disk, however, is a stop condition because the installer cannot safely target a disk it cannot see.

Open Terminal without copying the prompt

The Terminal is a text window where a command asks the system to do something. Open it from the application search or with Ctrl + Alt + T.

You may see a prompt similar to this:

Example prompt — do not typemiyuru@miyuru-7400:~$

The prompt identifies the user, computer, and current folder. It ends with $ for an ordinary user. Do not type or copy the prompt. The tilde ~ is a short name for the current user’s home folder; you do not need to use it in this check.

lsblk -o NAME,SIZE,TYPE,FSTYPE,MODEL,MOUNTPOINTS

Type the line exactly, then press Enter. It is a read-only listing command. It does not format or partition anything.

• lsblk means “list block devices,” such as disks and their partitions.
• -o is an option that selects output columns. The hyphen marks an option.
• The comma-separated names request these columns:
  • NAME: the system’s current device name.
  • SIZE: approximate capacity.
  • TYPE: disk, partition, or another block-device type.
  • FSTYPE: filesystem such as vfat when known.
  • MODEL: manufacturer or product model when reported.
  • MOUNTPOINTS: folders where a filesystem is currently attached.

Read a USB-only result

Here is an anonymized result based on a real beginner situation. It is sample output, not another command:

NAME    SIZE   TYPE FSTYPE MODEL   MOUNTPOINTS
sda     114.6G disk        SanDisk
└─sda1  114.6G part vfat            /cdrom

Several clues identify this as the installation USB:

• SanDisk matches the physical USB’s manufacturer.
• 114.6G is consistent with a USB sold around 128 GB; manufacturers and operating systems display capacity differently.
• Its partition uses vfat, a filesystem commonly present on boot media.
• The partition is mounted at /cdrom, which is strong context that the live system started from it.

The leading slash in /cdrom means the folder begins at the top, or root, of Ubuntu’s filesystem. It does not mean “a drive letter” as it would in Windows.

What is missing matters just as much: there is no expected 256 GB, 512 GB, or 1 TB internal disk in this sample.

Device names are clues, not identities

/dev/sda is not always the USB and is not always the internal disk. It is a name assigned for this boot. An internal NVMe SSD often appears as nvme0n1; an internal SATA disk might appear as sda; USB names can be sda, sdb, or something else depending on what was detected first.

Use a bundle of evidence:

• Model.
• Capacity.
• Which physical devices are connected.
• Filesystem and partitions.
• Mount point.
• Whether the entry matches the internal-drive details recorded before boot.

Never format a device based on its name alone.

Common mistakes and recovery

Copying the prompt with the command. Run only the lsblk line. If the shell says a username or hostname is not a command, clear the line and type only the command.

Assuming size must equal the package label. A 128 GB device can appear around 114–123 GB depending on units and layout. Match model and context too.

Treating a partition as a second disk. Indented entries such as sda1 belong to the disk above them.

Opening the installer because the desktop works. Hardware testing is not complete until internal storage is visible and identified.

Ignoring a failed suspend test. Resume failures can affect everyday reliability. Record them and seek model-specific support before committing the computer.

What to learn next

If the internal disk is missing, continue immediately to Ubuntu Installer Shows Only the USB Drive. If it is visible and hardware works, read Ubuntu Installation Options Explained before opening the installer.