Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have noticed that two files on my (almost full) 2 TB hard drive have been corrupted. One file has 20 kB (!) corrupted, i.e. consecutive 20 kB have changed, even though the modification date of the file hasn't changed and I haven't worked with this file for over a year. This tells me that something "below" the file system level has messed with the data and the only thing I can think of is hardware failure, most likely hard disk failure.

I've tested my RAM already and it works flawlessly. I'm using ext4 on Linux, if that is of any help.

Is this normal?

Is it time to change my hard drive disk before something worse happens?

What can I do to prevent that from happening in the future?

Is there some built-in feature of, or extension to ext4 that includes additional error correcting code and/or watches files for changes that haven't been caused by the OS?

share|improve this question
Most likely this is due to the system crashing at an inopportune time. Run chkdsk. (If you're really paranoid you can run the "check every sector" version, but don't plan on using the computer for 2-3 days.) – Daniel R Hicks Oct 13 '12 at 3:07
Thank you, I will do that. But, is your explanation possible, even though I last accessed this file long before the corruption (= potential crash) has happened? I always thought that a crashing system might corrupt files if they are being written to at the moment of the crash, but I never heard of a crashing system corrupting files that haven't even been accessed at the potential time of the crash. Is this still possible, and if so how? Thank you again! – Elipsicon Oct 13 '12 at 3:14
Take a look at S.M.A.R.T data of this drive. If this corruption is really hardware dependent then it should be reflected in the counters of errors/relocated sectors/e.t.c. – Serge Oct 13 '12 at 5:35

A corrupt file does not necessarily indicate a corrupt hard drive. File corruption can be caused by many different reasons. Bad drivers, firmware, incorrect shutdown, power surge, bad memory, CPU, electrical/magnetic interference, poorly written software, viruses, etc...

Check the hard drive with some testing tools for reliability. Otherwise, chalk it up to bad luck.

If you are consistently getting corruption, then you need to take a closer look.

share|improve this answer

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .