Re: Latest Jessie doesn't respond to /etc/default/tmpfs "RAMTMP=yes"
On Jul 28, 2014, at 1:00 PM, Andrei POPESCU <andreimpopescu@gmail.com> wrote:
> As a side note, I'd also be interested in the reasons for the default
> options set by the systemd tmp.mount unit (mode=1777,strictatime), a
> superficial web search did not find anything.
Just a guess…
mode=1777 sets all accesses allowed (it is “/tmp” after all…) and also sets the “sticky bit” which (according to stat(2)) “on a directory means that a file in that directory can be renamed or deleted only by the owner of the file, by the owner of the directory, and by a privileged process.”
“strictatime” (according to mount(8)) "Allows to explicitly requesting full atime updates. This makes it possible for kernel to defaults to reltime or native but still allow userspace to override it.”
So in an embedded system with root on flash, but /tmp in RAM, we get standard semantics for atime (no need to be nice to flash since the whole filesystem is in RAM) and the usual expected behavior for deletion/rename operations in /tmp.
It’s what I would have done, if I had thought about the issue. In general, I’m glad there are so many nice folks out there thinking about these issues, so I don’t have to! (-;
Rick
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