Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Fact or fiction without any friction, I have heard in passing on the web only about 2 times, that hard drives will re-write the data onto the platter when Only reading the data off of that platter.

Question applies to modern normal consumer hard drives with spinning platters, and read/write heads.

Do hard drives really re-write data when only reading data from the drive?

If i am supposed to have a specific problem, then: For very long term storage of data, if this is actually true, then reading the data once a year could insure a better magnetic polarity differance. For long term storage not only would it be good to spin it up and get the motor moving, but to do a read of the data one time.

share|improve this question

closed as not constructive by Diago Oct 18 '11 at 17:00

As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, visit the help center for guidance.If this question can be reworded to fit the rules in the help center, please edit the question.

    
What is your probelm you'd like solved. I'm considering flagging this question. –  wizlog Oct 18 '11 at 16:49
add comment

2 Answers 2

up vote 4 down vote accepted

Reading occurs more often than just when you execute a file. So it may appear to some that this is the case. But the reading that occurs is always at the request of running software.

Wizlog is correct, when the drive is ONLY reading, it will not re-write the data. However, metadata is usually recorded when the files are read. For instance, in Windows you can view the Date Last Accessed, which is not the last time the file was modified, but the date the file was last opened. While the file data may not have been modified when the file was accessed, the meta-data associated to that file was written to record the fact the file was accessed.

Also, the system may be reading and writing at any given time when instructed to do so by software.

In an investigation when people wish to view the contents of a drive without in any way modifying the data, you'll use special read-only hard drive interfaces which will allow the system to read the data while preventing any meta-data, or any other data, from being written to the drive.

share|improve this answer
    
Thanks, the persons on the web saying it portrayed that they had some knowledge of the internal workings of the hard drive. Thier statements were never countered or questioned, in the threads. Mabey they were confused by the updating of the minor data. –  Psycogeek Oct 18 '11 at 17:07
    
@music2myear thanks for the credit. –  wizlog Oct 19 '11 at 16:48
add comment

No. It does not. When your HDD is reading data, it uses the read part of the read-and-write head. When writing data, it uses the write part of the head. When doing both, it uses both.

share|improve this answer
add comment

Not the answer you're looking for? Browse other questions tagged or ask your own question.