Is my Hard disk is usable

Bree said:

Reallocated sectors are sectors that have been found to be permanently faulty and have been remapped to use spare sectors from an area the drive has set aside for this purpose. Pending sectors are ones that have been detected as possibly faulty but (for now) are in use and can be read. When not in use they can be tested again (such as by doing a full format) and will be reallocated should the diagnosis prove correct. Should they pass the test they will be removed from the 'pending' list and returned to use.

According to Backblaze, who know a thing or two about predicting drive failures, the key warning signs to look for are...

Attribute		Description
SMART 5		Reallocated Sectors Count
SMART 187		Reported Uncorrectable Errors
SMART 188		Command Timeout
SMART 197		Current Pending Sector Count
SMART 198		Uncorrectable Sector Count

Read this blog from Backblaze for full details...
https://www.backblaze.com/blog/what-...rive-failures/

Thanks, very knowledgable blog.

dalchina said:

Hard Disk Sentinel (not free, but giveaways periodically) will monitor your disks' condition - different alarms available.

Crystal Diskinfo can also monitor your disks and generate an alarm, but the help info (not native English) is sparse and hard to grasp.
Resident Crystal Dew World

Routine disk imaging may well pick up disk data corruption- CRC errors- but by that time some data will be lost.

More:
Best Free Hard Drive Health Monitoring and Diagnostic Programs | Gizmo's Freeware
14 Free Hard Drive Testing Tools (Updated June 2018)

Thanks