Tech Tip: "Enable the at/batch command for root by adding root to /usr/lib/cron/at.allow" Error during eHealth install on Linux

Document created by Darshan_Desai Employee on Dec 8, 2014Last modified by SamCreek on Dec 17, 2016
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During the install (or upgrade) on Linux, following error may occur:


The at/batch command must be enabled for the root user.

Error: Enable the at/batch command for root by adding root to /usr/lib/cron/at.allow




This is not an issue with at.allow or at.deny files, rather its a system resource or permission.



There are 2 likely causes for this.


The first and most common is using any form of sudo for the install. The install requires the root password, and no form of sudo is supported.

See the Install Linux steps.




Another possible cause is if the machine is working too hard.

eHealth uses the at.batch command to write a file to tmp and then it checks if the file is there. If it is not, install exists with this at/batch error.


If you run "man at", it will provide following information:

batch executes commands when system load levels permit; in other words, when the load average drops below 0.8, or the  value  specified in the invocation of atrun.





To see load, run top and look at the top line.

top - 08:08:29 up 59 days, 17:55,  2 users,  load average: 0.10, 0.06, 0.01


In the example above, we see that load is 0.10. This load is too high to allow the at/batch command to run. Please check the load on your system, it must be below 0.8 for the install to run.

See why the machine is busy. Open a second terminal to the host and run top at the same time as the install, if load goes over .08, the install will fail.


Please consider to stop eHealth and web before running install. This will help reduce the load, and install to run.