# Docker shm\_size Option in app.yml

**URL:** https://meta.discourse.org/t/docker-shm-size-option-in-app-yml/174067
**Category:** Feature
**Created:** [December 23, 2020, 2:32am UTC](https://meta.discourse.org/t/docker-shm-size-option-in-app-yml/174067 "2020-12-23T02:32:44Z")
**Posts on this page:** 1
**Showing post:** 10

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### Author: ![neounix](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/neounix/32/215617_2.png) [@neounix](https://meta.discourse.org/u/neounix)
#### Post date: [December 29, 2020, 5:39am UTC](https://meta.discourse.org/t/docker-shm-size-option-in-app-yml/174067/10 "2020-12-29T05:39:45Z")

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> [@Ghan](#):
>
> I’m not sure. Does that overwrite the launcher file itself? I see 3 places where the option is hardcoded:

Hey @Ghan

In the meantime (for testing purposes, see caveat below), you can change this directly with docker after the container is built, as follows:

- Edit the `/var/lib/docker/containers/$CONTAINER_ID/hostconfig.json` file directly.
- For example, change the value for `ShmSize` in the file above.
- Stop and restart the container.

In our docker container hostconfig file, it looks like this:

```plaintext
"ShmSize":536870912,

```

 ![Screen Shot 2020-12-29 at 12.39.17 PM](https://global.discourse-cdn.com/meta/original/3X/5/7/571fdd1f3bb03cce6e6882be828abd6dfda022d1.jpeg)

HTH

Caveat: Some people have posted that you must make sure that docker service is stopped before you modify hostconfig.json (or the changes will be overwritten). However, I have not actually tested this. Obviously a `launcher` solution is better 🙂

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