Revisions to What's the difference between /tmp and /run?

Link to FHS-3.0 for those of us who don't know what it is

edit approved Aug 16, 2017 at 18:48

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According to FHS-3.0FHS-3.0, /tmp is for temporary files and /run is for run-time variable data. Data in /run must be deleted at next boot, which is not required for /tmp, but still programs must not assume that the data in /tmp will be available at the next program start. All this seems quite similar to me.

So, what is the difference between the two? By which criterion should a program decide whether to put temporary data into /tmp or into /run?

According to the FHS:

Programs may have a subdirectory of /run; this is encouraged for programs that use more than one run-time file.

This indicates that the distinction between "system programs" and "ordinary programs" is not a criterion, neither is the lifetime of the program (like, long-running vs. short-running process).

Although the following rationale is not given in the FHS, /run was introduced to overcome the problem that /var was mounted too late such that dirty tricks were needed to make /var/run available early enough. However, now with /run being introduced, and given its description in the FHS, there does not seem to be a clear reason to have both /run and /tmp.

According to FHS-3.0, /tmp is for temporary files and /run is for run-time variable data. Data in /run must be deleted at next boot, which is not required for /tmp, but still programs must not assume that the data in /tmp will be available at the next program start. All this seems quite similar to me.

So, what is the difference between the two? By which criterion should a program decide whether to put temporary data into /tmp or into /run?

According to the FHS:

Programs may have a subdirectory of /run; this is encouraged for programs that use more than one run-time file.

This indicates that the distinction between "system programs" and "ordinary programs" is not a criterion, neither is the lifetime of the program (like, long-running vs. short-running process).

Although the following rationale is not given in the FHS, /run was introduced to overcome the problem that /var was mounted too late such that dirty tricks were needed to make /var/run available early enough. However, now with /run being introduced, and given its description in the FHS, there does not seem to be a clear reason to have both /run and /tmp.

According to FHS-3.0, /tmp is for temporary files and /run is for run-time variable data. Data in /run must be deleted at next boot, which is not required for /tmp, but still programs must not assume that the data in /tmp will be available at the next program start. All this seems quite similar to me.

So, what is the difference between the two? By which criterion should a program decide whether to put temporary data into /tmp or into /run?

According to the FHS:

Programs may have a subdirectory of /run; this is encouraged for programs that use more than one run-time file.

This indicates that the distinction between "system programs" and "ordinary programs" is not a criterion, neither is the lifetime of the program (like, long-running vs. short-running process).

Although the following rationale is not given in the FHS, /run was introduced to overcome the problem that /var was mounted too late such that dirty tricks were needed to make /var/run available early enough. However, now with /run being introduced, and given its description in the FHS, there does not seem to be a clear reason to have both /run and /tmp.

retag (/run is only on linux and the question talks about the fhs, which is also linux-only)

Link

edit approved Oct 20, 2016 at 9:45

Martin Schröder

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Tweeted twitter.com/StackUnix/status/786652841784016898

occurred Oct 13, 2016 at 19:40

Added the point about FHS encouraging "ordinary progams" to also use /run in certain circumstances.

Source Link

edited Oct 13, 2016 at 12:54

Dirk Herrmann

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According to FHS-3.0, /tmp is for temporary files and /run is for run-time variable data. Data in /run must be deleted at next boot, which is not required for /tmp, but still programs must not assume that the data in /tmp will be available at the next program start. All this seems quite similar to me.

So, what is the difference between the two? By which criterion should a program decide whether to put temporary data into /tmp or into /run?

According to the FHS:

Programs may have a subdirectory of /run; this is encouraged for programs that use more than one run-time file.

This indicates that the distinction between "system programs" and "ordinary programs" is not a criterion, neither is the lifetime of the program (like, long-running vs. short-running process).

So, whatAlthough the following rationale is not given in the difference betweenFHS, /run was introduced to overcome the two? By which criterion should a program decide whetherproblem that /var was mounted too late such that dirty tricks were needed to put temporary data intomake /tmpvar/run or intoavailable early enough. However, now with /run? being introduced, and given its description in the FHS, there does not seem to be a clear reason to have both /run and /tmp.

According to FHS-3.0, /tmp is for temporary files and /run is for run-time variable data. Data in /run must be deleted at next boot, which is not required for /tmp, but still programs must not assume that the data in /tmp will be available at the next program start. All this seems quite similar to me.

According to the FHS:

Programs may have a subdirectory of /run; this is encouraged for programs that use more than one run-time file.

This indicates that the distinction between "system programs" and "ordinary programs" is not a criterion.

So, what is the difference between the two? By which criterion should a program decide whether to put temporary data into /tmp or into /run?

According to FHS-3.0, /tmp is for temporary files and /run is for run-time variable data. Data in /run must be deleted at next boot, which is not required for /tmp, but still programs must not assume that the data in /tmp will be available at the next program start. All this seems quite similar to me.

So, what is the difference between the two? By which criterion should a program decide whether to put temporary data into /tmp or into /run?

According to the FHS:

Programs may have a subdirectory of /run; this is encouraged for programs that use more than one run-time file.

This indicates that the distinction between "system programs" and "ordinary programs" is not a criterion, neither is the lifetime of the program (like, long-running vs. short-running process).

Although the following rationale is not given in the FHS, /run was introduced to overcome the problem that /var was mounted too late such that dirty tricks were needed to make /var/run available early enough. However, now with /run being introduced, and given its description in the FHS, there does not seem to be a clear reason to have both /run and /tmp.