Re: strange disk activity [tail -f]
Albert Cahalan (albert@ccs.neu.edu)
Wed, 3 Apr 1996 16:07:01 -0500 (EST)
> > I'm getting this sort of behaviour too. 1.3.80, there is disk activity
> > every five or six seconds. procinfo says it's most often writing about
> > three pages, but this varies. Under 1.2.13, on the same system, the
> > closest I got to this was the minutely atrun. In both cases I have
> > continuously running processes, including a top and three tail -fs. I
> > suspect that the tails are what is causing this.
>
> yep, "tail -f" reads (polls) the file every second, this in turn changes
> the atime field, and bdflush updates the inode and the superblock.
Aside from /tmp on a large system, I'd have to say that atime is
rather useless. I'd be interested in a mount option to disable
atime tracking. There might be a performance increase when doing
reads, and it would help laptop users because disk activity
reduces battery life.