Is it wasteful to call cat?

I’m sorry if this question is really stupid, but this is basically what I have been thinking about constantly. Suppose I run:

: cat ./somefile.txt

A few hundred times a second. How much faster is my hard drive going to die?

Seven. But seriously, it's hard enough to know how long a disk will last while idling let alone under heavy load. There's no answer other than to say it will probably wear the disk faster.

The better argument against this is it would generally be quite slow. Why would you need to hammer the disk like that?

If you're looking to find out when something changes, perhaps look at inotify which is a kernel-based file event system that can call some code when something happens, negating the need to hammer the disk.

There are wrappers like pyinotify to make things easier.

It may have no effect at all, depending on the size of somefile.txt - if it's small enough for the kernel to cache it in RAM, the file will only be read once from disk and subsequent iterations will retrieve it from the cache.

Even if running that command repeatedly does have an effect on your drive's lifetime, it will be due to the file being read repeatedly. Whether you use cat or some other program to read it is completely irrelevant.

This reminds me of that study Google did about Harddrives. Since they go through a lot of harddrives, they did an informal study to see if there was any significant correlation between the lifetime of a HD and a list of factors that include temperature, power cycles, activity levels, etc. The only significant factor they found was age, I believe. The study is called "Failure Trends in..." something something.

I wouldn't worry too much about HD usage eating your drive.