On Sun, Nov 25, 2012 at 12:17:21PM -0800, John Hardin wrote:

> I'm unfamiliar with SunOS. What is "swap" and why it is mounted on
> /tmp? Seeing something called "swap" mounted as a real filesystem is
> making me twitch. Is that some sort of ramdisk?

It's the Solaris tmpfs.  Surplus virtual memory is mounted as swap.
While the system has plenty of memory left, it's effectively a ramdisk.
Only when memory usage goes up does it use some paging area on your hard
disks.  This makes /tmp very fast in normal circumstances.  Disadvantage:
Unless you limit the maximum size of /tmp, a runaway process writing
to /tmp can fill up your swap space.  (Similar to the way a runaway
process allocating memory can fill it up, but of course it's another
path to doom...)

Regards,
Marc

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