Understanding Why h2testw Sometimes Cannot Test the Full Capacity of Your Memory Card
If you’ve encountered a message from the utility h2testw indicating “Warning: Only 30,510 of 30,511 MByte tested” on your storage device, you might be wondering what this means and whether it should cause concern. Many users who test their SD cards or USB drives with h2testw notice that the program doesn’t always verify the entire capacity of their storage media, yet it still reports that the tested portion is functioning correctly. In this article, we’ll explore the reasons behind this behavior and provide guidance on whether further action is necessary.
Understanding h2testw and Its Testing Process
h2testw is a popular utility used to verify the integrity of flash storage devices such as SD cards, USB drives, and solid-state drives. It writes test data across the device’s storage space and then reads back to ensure data integrity. This process helps identify counterfeit or faulty storage media that may falsely report higher capacities or fail prematurely.
Why Does the Test Occasionally Stop Short of the Full Capacity?
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Partitioning and Formatting Limitations:
Sometimes, a device might be partitioned or formatted in a way that the utility cannot fully access the entire storage space. For instance, a device might have hidden partitions or a filesystem that doesn’t span the entire capacity, preventing full testing. -
File System or Firmware Restrictions:
Certain devices have firmware limitations or specialized file systems that prevent reading or writing to every byte of storage uniformly. This can result in the testing utility stopping short. -
Manufacturing Variances and Fake Storage Devices:
Counterfeit or misrepresented storage devices might report a higher capacity than they actually possess. When the utility attempts to verify the entire capacity, it reaches unallocated or non-existent storage, which leads to partial testing. -
Bad Sectors or Failing Memory Cells:
Even if the device is generally functional, minor bad sectors can cause the utility to halt the full test to prevent data corruption or prolonged testing times.
Should You Be Worried?
In most cases, if h2testw reports that “everything that was tested is fine,” and only a small portion of the total capacity was untested, the device is likely still reliable. However, it is important to consider:
- The Extent of the Untested Area:
If only a tiny fraction of the total capacity remains untested, it’s generally not a cause for alarm
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