I am new to here, and I hope you ll help with my questions already in mind for some time. Thanks.
1. what is the average life-span of an internal and external harddisk? I know problems and fatal errors or death could happen to the harddisks without knowing in advance.
2. what is the software I should use to keep track of the condition of the harddrive?
3. what are the technical terms to describe the problems that could happen to the harddrive? I only know "bad sector", are there any such terms else?
4. for both external and internal harddrive, what is the most common problem /error that occurred to normal user?
5. If I don't find any problems with the diagnostic software for an old harddrive, does it imply that the harddrive works as perfectly as the freshly bought one.
what I mean is - if I have a file on the harddisk, but after some time, the physical components of the harddrives get damaged/altered/aging, will it be possible that the file be also damaged/altered/corrupt (more universally - be changed) but it has no error message / notice to the user? and he nevers know his file are changed even very slightly.
Internal hard drives will last you longer and be more reliable, just look at the hundreds of posts in the forums about external drives that are no longer recognized, mainly due to user error (unplugging when data is still being written). Also, in my experience notebook drives die sooner, probably a heat related issue.
Some internal drives still have 5 year warranties and I have very few drives that have died in the past 15 years, most get tossed for being too small.
You can check the status of your drives with either manufacturer test programs or crystaldiskinfo, which is a freeware download. Both monitor the SMART attributes of a drive looking for an early warning of problems.
Bad sectors are not a big deal, they get re-mapped and are not used. The big deal is a major hardware malfunction like the read/write heads crashing into the disk platter (a head crash) -- much more common on external drives as they get knocked over while operating.
Your files won't change on you, but disk errors can occur, although uncommon, and drive failure is always a possibility so back up.
All of my old drives still work fine, but after years of 24/7 use they may rate as perfectly good, but eventually they will die since they are mechanical devices.