[Pkg-sysvinit-devel] Bug#691673: initscripts: please, allow having /run *not* being a RAM disk.

[Roger Leigh]

On Sun, Oct 28, 2012 at 10:02:57AM -0200, Rogério Brito wrote:
> For those people that want to shoot themselves on their own foot, please
> allow (even if undocumented) running with /run *not* being a ramdisk.
> 
> This is especially important for memory-starved machines like embedded
> computers/NASes, where every single byte of RAM is important.

We aleady do allow this.  Just comment out the
mount_run and mount_lock lines in /etc/init.d/mountkernfs.sh.
We allow RAMLOCK to turn off /run/lock; we don't expose a
RAMRUN to allow /run to be turned off--you do need to edit
the script directly.

The bootclean logic for cleaning /run still exists, so it
will continue to work without it being a tmpfs.

However... note that this would be done *entirely* at the
user's risk.  The reason for making /run a tmpfs unilaterally
was mainly so that it could be relied upon to *be* a tmpfs,
and so software can therefore assume that a tmpfs is present.
This is primarily so that software services started in the
initramfs can retain their state and open files from early
boot through to the running system.  Examples: udev, mdadm.
While these also have codepaths to allow booting in the
absence of an initramfs, it is possible that in the future
these or other services will require a tmpfs.


Regards,
Roger

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