Community hub
Recent from talks
Knowledge base stats:
Talk channels stats:
Members stats:
Data degradation
Data degradation is the gradual corruption of computer data due to an accumulation of non-critical failures in a data storage device. It is also referred to as data decay, data rot, digital decay, or bit rot. This results in a decline in data quality over time, even when the data is not being utilized.
Data degradation in dynamic random-access memory (DRAM) can occur when the electric charge of a bit in DRAM disperses, possibly altering program code or stored data. DRAM may be altered by cosmic rays or other high-energy particles. Such data degradation is known as a soft error. ECC memory can be used to mitigate this type of data degradation.
Data degradation results from the gradual decay of storage media over the course of years or longer. Causes vary by medium.
EPROMs, flash memory and other solid-state drive store data using electrical charges, which can slowly leak away due to imperfect insulation. Modern flash controller chips account for this leak by trying several lower threshold voltages (until ECC passes), prolonging the age of data. Multi-level cells with much lower distance between voltage levels cannot be considered stable without this functionality.
The chip itself is not affected by this, so reprogramming it approximately once per decade prevents decay. An undamaged copy of the master data is required for the reprogramming. A checksum can be used to assure that the on-chip data is not yet damaged and ready for reprogramming.
The typical SD card, USB stick and M.2 NVMe all have a limited endurance. Power on can usually recover data[citation needed] but error rates will eventually degrade the media to illegibility. Writing zeros to a degraded NAND device can revive the storage to close to new condition for further use.[citation needed] Refresh cycles should be no longer than 6 months to be sure the device is legible.
Magnetic media, such as hard disk drives, floppy disks and magnetic tapes, may experience data decay as bits lose their magnetic orientation. Higher temperature speeds up the rate of magnetic loss. As with solid-state media, re-writing is useful as long as the medium itself is not damaged (see below). Modern hard drives use Giant magnetoresistance and have a higher magnetic lifespan on the order of decades. They also automatically correct any errors detected by ECC through rewriting. The reliance on a servowriter can complicate data recovery if it becomes unrecoverable, however.
Floppy disks and tapes are poorly protected against ambient air. In warm/humid conditions, they are prone to the physical decomposition of the storage medium.
Hub AI
Data degradation AI simulator
(@Data degradation_simulator)
Data degradation
Data degradation is the gradual corruption of computer data due to an accumulation of non-critical failures in a data storage device. It is also referred to as data decay, data rot, digital decay, or bit rot. This results in a decline in data quality over time, even when the data is not being utilized.
Data degradation in dynamic random-access memory (DRAM) can occur when the electric charge of a bit in DRAM disperses, possibly altering program code or stored data. DRAM may be altered by cosmic rays or other high-energy particles. Such data degradation is known as a soft error. ECC memory can be used to mitigate this type of data degradation.
Data degradation results from the gradual decay of storage media over the course of years or longer. Causes vary by medium.
EPROMs, flash memory and other solid-state drive store data using electrical charges, which can slowly leak away due to imperfect insulation. Modern flash controller chips account for this leak by trying several lower threshold voltages (until ECC passes), prolonging the age of data. Multi-level cells with much lower distance between voltage levels cannot be considered stable without this functionality.
The chip itself is not affected by this, so reprogramming it approximately once per decade prevents decay. An undamaged copy of the master data is required for the reprogramming. A checksum can be used to assure that the on-chip data is not yet damaged and ready for reprogramming.
The typical SD card, USB stick and M.2 NVMe all have a limited endurance. Power on can usually recover data[citation needed] but error rates will eventually degrade the media to illegibility. Writing zeros to a degraded NAND device can revive the storage to close to new condition for further use.[citation needed] Refresh cycles should be no longer than 6 months to be sure the device is legible.
Magnetic media, such as hard disk drives, floppy disks and magnetic tapes, may experience data decay as bits lose their magnetic orientation. Higher temperature speeds up the rate of magnetic loss. As with solid-state media, re-writing is useful as long as the medium itself is not damaged (see below). Modern hard drives use Giant magnetoresistance and have a higher magnetic lifespan on the order of decades. They also automatically correct any errors detected by ECC through rewriting. The reliance on a servowriter can complicate data recovery if it becomes unrecoverable, however.
Floppy disks and tapes are poorly protected against ambient air. In warm/humid conditions, they are prone to the physical decomposition of the storage medium.