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cm_processes question

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cm_processes question

Explorer

My understanding of the cm_processes tmpfs is that it is for issues on systems where /var is a no ext mount. We are running on RHEL 6.5 and /var is ext4. Is there a way to prevent CM from mounting this filesystem or, if not, adjusting its size? 

 

Thanks

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Accepted Solutions

Re: cm_processes question

Cloudera Employee

Hi Greg,

 

It's required for distros where /var/run is mounted noexec but we use it unconditonally so that the Agent is operating in a consistent environment across all distros, and certain bits of agent functionality take advantage of this (such as our logic for cleaning out /var/run/cloudera-scm-agent, which unmounts and remounts the tmpfs).

 

What is your concern? Do you have a particular problem you are trying to solve?

 

Thanks,

3 REPLIES 3

Re: cm_processes question

Cloudera Employee

Hi Greg,

 

It's required for distros where /var/run is mounted noexec but we use it unconditonally so that the Agent is operating in a consistent environment across all distros, and certain bits of agent functionality take advantage of this (such as our logic for cleaning out /var/run/cloudera-scm-agent, which unmounts and remounts the tmpfs).

 

What is your concern? Do you have a particular problem you are trying to solve?

 

Thanks,

Re: cm_processes question

Explorer

Our OS team was asking about this because they saw the tmpfs filesystem allocated to 50% of memory. We weren't able to find a lot of documentation on it and were trying to determine if it was necessary and if so why. This has not caused any issues. I will pass the information along. Thanks.

Re: cm_processes question

Cloudera Employee

A tmpfs will default to a max size of 50% of physical RAM but this space is not allocated until its used, and tmpfs will be paged out to swap if there is memory pressure.