How does Cropel monitor hard drive health?

Cropel Hard Drive Diagnostic software uses both S.M.A.R.T. data of a particular storage device (a hard drive or an SSD) and S.M.A.R.T. data available in the Cropel database about other devices of the same model.

Cropel requests data about state of the data storage devices once every five minutes. Obtained S.M.A.R.T. data is analyzed and, should the need arise, the message about a disk failure is displayed. If a PC is connected to the Internet, Cropel sends the latest S.M.A.R.T. attribute data to the database every 30 minutes.

Cropel database is designed to store S.M.A.R.T. attribute data of all data storage devices on which Cropel Hard Drive Diagnostic software is working. The database is used to:

• predict a possible disk failure,
• compare S.M.A.R.T. data of a particular device with S.M.A.R.T. data of similar devices (the same model and revision).

How reliable are the predictions?

Based on S.M.A.R.T. data it is only possible to predict those failures which are caused by slowly developing defects of a storage device. Imminent failures caused by e.g. dropping a hard drive, voltage spikes, or spindle lock up are not predicted at all.

On average, it is possible to predict approximately half of failures based on S.M.A.R.T. data.

What device characteristics are monitored by Cropel?

Different attribute groups describe different aspects of hard drive health. The following is a list of various device characteristics along with a list of corresponding S.M.A.R.T. attributes.

• Hard disk surface state (read/write) (e.g. Read Error Rate, Reallocated Sectors Count, and Current Pending Sector Count).
• State of the heads and positioning system (e.g. Seek Error Rate, Seek Time Performance, and GMR Head Amplitude).
• Estimated remaining lifetime depending on cycles count, how much data has been written (it is important for an SSD) (e.g. Start/Stop Count, Power On Hours, and Total LBAs Written).
• State of flash memory in regards to an SSD (e.g. Reallocated Sectors Count and Available Reserved Space).
• Mechanical state of a device and characteristics of the environment in which a device operates - shocks, drops, vibrations, and temperature (e.g. Temperature, G-Sense Error Rate, and Free Fall Protection).

For full list of S.M.A.R.T. attributes which are handled by Cropel see this page.