Understanding the PERSIST Partition in Android By Mofadal El-Taye

Understanding the PERSIST Partition in Android By Mofadal El-Taye

In earlier articles, we discussed NVRAM and NVDATA, two important partitions in the Android system. Today we continue with another sector that often causes confusion: PERSIST.

Many users think it is the same as the “persistent” partition used on Samsung phones for FRP (Factory Reset Protection). This is not true. The PERSIST sector has a different role, and its use changes depending on the processor type and the device brand.

What is the PERSIST Partition?

The PERSIST partition is usually formatted in EXT4 (sometimes with ext2 subfiles). This makes it possible to open and explore its contents with tools such as 7zip, Android Utility FS Explorer, or other ROM/file system utilities.

The purpose of this partition depends on the chipset and vendor.

Usage on Spreadtrum / UniSoC Devices

On devices with Spreadtrum (SPD) or UniSoC processors, the PERSIST partition is relatively simple:

• It works mainly as an FRP partition.
• On brands like Infinix, Tecno, and Itel, it may also store MDM (Mobile Device Management) data and leftover setup files.
• Keys are usually located at:

PERSIST/paytrigger

So, in these devices, the partition mainly handles FRP and MDM-related data.

Usage on Qualcomm Devices

On Qualcomm-powered devices, the PERSIST partition has a much larger role. It contains calibration data, which is essential for hardware performance.

Stored data may include:

• Sensor calibration (proximity, gyroscope, etc.)
• Wi-Fi and Bluetooth calibration
• Camera configuration
• Sound and volume levels
• Fingerprint data
• Network frequency settings

If this partition is corrupted, the device may lose key features.

Examples:

• On Huawei DUB-LX1, replacing the PERSIST partition often caused sound problems.
• On Xiaomi devices, incorrect PERSIST partitions led to camera and sensor failures.

Brand-Specific Functions

Xiaomi

• The PERSIST partition stores Mi Account data at:

  PERSIST/fdsd/st
  

• This includes the account ID, number, and a session key used for communication with Xiaomi servers.

• If deleted, the account lock may disappear temporarily, but it will return once the device connects to the internet.

Huawei

• Huawei ID data is stored at:

  PERSIST/data/xx
  

• Deleting or renaming these files can result in account errors or even chip-level damage.

Infinix / Tecno / Others

• These brands also use the partition for account or ID information, but the structure is different. (We will discuss these cases in future articles).

Why is PERSIST Important?

Although small, the PERSIST partition is critical because it affects:

• Hardware calibration (sound, sensors, camera, fingerprint)
• Account security (Mi Account, Huawei ID, FRP, MDM)

If damaged, the device may lose features or become locked.

A Practical Tip

If you want to understand it better:

1. Open a firmware (official or backup) in Android Utility FS Manager.
2. Browse the PERSIST partition.
3. Compare files across different chipsets and brands.

This hands-on practice will clearly show how each vendor uses the partition differently.