Without digging into the rationale behind access time tracking, its write-amplification effects in particular for SSDs, or the fact that it can be somewhat mitigated by the relatime and lazytime mount options:

Can we produce a list of the (allegedly very few) applications that actually require atime support, and how (severely) they break if it's not used?

Naturally, a number of applications that inspect atime indirectly rely on it, in the sense that they report a wrong atime if it is not tracked (e.g., listing or forensic tools). This question should only concern applications that actually exploit this piece of information, rather than presenting it, and which break at least to some extent functionality-wise if they are used on data without atime support (e.g., the prime example of mails not shown as read).

closed as too broad by Rui F Ribeiro, Stephen Kitt, Mr Shunz, JigglyNaga, muru Apr 18 at 14:49

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • mailx
  • mutt: "new mail" status depends on atime
    only if used with mbox or mmdf mailboxes; Maildir and MH folders do not rely on atime (reference); partial workaround: $check-mbox-size option
  • procmail
  • tmpwatch: deletes files that have not been accessed for a long time
    usually run on tmpfs only
  • ... (please add your piece of information here)

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