Re: mountkernfs, mountvirtfs, and devpts.sh
In article <[🔎] 20040427211738.GA5351@hank.org>,
Bill Moseley <firstname.lastname@example.org> wrote:
>I'm not using tmpfs for anything that I know of. That's why I didn't
>enable it on my last kernel build. Do systems expect that tmpfs will
>be available? I see I've got it enabled on other machines but /dev/shm
>is empty. Why use the RAM if it's not needed.
It's not using any RAM if you don't use it. As far as I understand
it, the kernel uses an internal mount of tmpfs for SysV shared
memory support, and when tmpfs is enabled you can use an
external mount (on /dev/shm) for POSIX shared memory support,
and you can also use that as a real temp fs.
>[BTW -- can tmpfs get swapped to disk? That would seem to defeat the
>purpose, I guess.]
Tmpfs pages can get swapped, yes.
>I guess I was trying to understand devpts by asking a question. I'm not
>entirely clear what devpts is or does and why it's needed and when it's
>not. Does it only provide the ALT+Fn virtual terminal switching or is
>is needed for ssh'ing into the box?
>What would happen if it didn't get
Depends on the application. If it supports BSD style pty's and you
have those in /dev you won't much notice.