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A comment on Save your disk, write files directly into RAM with /dev/shm. Parent comment

Re:Save your disk, write files directly into RAM with /dev/shm by AdieuToLogic on Friday June 27, 2025 @05:30PM (#44400424)
> tmpfs will swap.

We are both wrong to a degree, but you are more correct than I was.

According to the docs[0]:

  tmpfs ... is able to swap unneeded pages out to swap
  space, if swap was enabled for the tmpfs mount.
So `tmpfs` does not unconditionally use swap, but can use it if possible. What I was thinking about is `ramfs`, which doesn't support swap, but that is not the topic of the question to which I replied.

0 - https://www.kernel.org/doc/html/latest/filesystems/tmpfs.htm...

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Re:Save your disk, write files directly into RAM with /dev/shm by buckle8017 on Saturday June 28, 2025 @03:53AM (#44402971)
You have to explicitly disable swap.

Honestly had no idea that was an option because I've never seen it disabled anywhere before.

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Re:Save your disk, write files directly into RAM with /dev/shm by AdieuToLogic on Sunday June 29, 2025 @09:46PM (#44418383)
> You have to explicitly disable swap.

> Honestly had no idea that was an option because I've never seen it disabled anywhere before.

Disabling swap is common with embedded systems, such as network gateways, routers, and other devices having no intrinsic mass storage devices.

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Re:Save your disk, write files directly into RAM with /dev/shm by buckle8017 on Wednesday July 09, 2025 @06:47AM (#44508373)
No like there's a tmpfs mount flag to not allow swapping.
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