Fix “Squashfs Error: Failed to Read Block” (Linux USB Boot Solution)

SQUASHFS error: Failed to read block

If you are seeing “SQUASHFS error: Failed to read block” (wording can vary slightly by Linux distro/version), it usually means the system cannot reliably read data from the boot media. This guide walks you through the fastest fixes in the right order.

Quick diagnosis:
  • Most common: bad USB port / hub / loose connection
  • Very common: corrupted ISO download or incomplete USB write
  • Common: low-quality / failing USB flash drive
  • Rare: faulty RAM (usually only after multiple USBs + multiple ISOs still fail)
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SQUASHFS error failed to read block screenshot

What Causes This Error?

SQUASHFS is a compressed filesystem used by many Linux live environments and installers. This error usually appears when the system hits read errors while loading blocks from the USB.

  • Bad / low-quality USB flash drive (read errors under sustained load)
  • Corrupted ISO download (incomplete or damaged file)
  • Incomplete / failed write to the USB drive
  • Unstable USB port / hub / loose connection (especially front ports)
  • Faulty RAM (less common, but possible)

Fix Steps (Try in This Order)

1) Power-cycle and reseat the USB
  • Turn off the computer completely.
  • Unplug the Linux USB flash drive.
  • Turn the computer back on once (without the USB), then power off again.
  • Plug the USB back in firmly and boot from it.
Need help booting from USB? How to boot from a USB drive
2) Switch USB ports (very common fix)
  • Desktop: use a rear motherboard port (avoid front panel ports).
  • Avoid USB hubs/extension cables while installing.
  • If you have both USB 2.0 and USB 3.0, try the other type.
3) Recreate the bootable USB (ISO corruption / bad write)

If the error repeats, assume the image on the USB is corrupted or incomplete.

  • Re-download the ISO from the official site.
  • Verify the ISO hash/checksum if provided (recommended).
  • Rewrite the USB using a reliable tool (Rufus, BalenaEtcher, Ventoy, etc.).
Installing Linux fresh? Installing Linux on a PC
4) Try a different USB flash drive

Some USB drives fail under sustained read load even if they “seem fine” for file storage. If you have another USB, try it.

5) Rare case: test RAM (only if nothing else works)

If the same error occurs across multiple USB drives and multiple fresh ISO downloads, faulty RAM can be the root cause. Running a memory test (Memtest86+) can help confirm.

Recommended Products (Reliable Alternatives)

If you want to skip ISO flashing issues and reduce boot errors, these are popular options:

Linux Mint Bootable USB
Linux Mint Bootable USB

A clean, beginner-friendly Linux environment — verified and ready to boot.

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Linux 8-in-1 Multi-Boot USB
Linux 8-in-1 Multi-Boot USB

Multiple Linux options in one toolkit — handy if one distro is picky on your hardware.

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Penguin Ultimate USB 128GB
Penguin Ultimate USB (128GB)

Full rescue toolkit: Linux + Windows recovery + troubleshooting tools in a clean boot menu.

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WiFi USB Dongle (Linux compatible)
Wi-Fi USB Dongle (WIF01)

Useful when troubleshooting Linux live boot environments that have no working Wi-Fi drivers.

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