Streange behavior for tmpfs?

[Paul Goyette <paul%whooppee.com@localhost>]

While attempting to update one of my source trees, using

        cvs -P -d -D 'a-few-minutes-ago'

I started getting the following error message:

        cannot create_adm_p /tmp/cvs-serv23337/usr.sbin/dumpfs
        No space left on device

(The file changes on subsequent attempts.)

My /tmp is rather large, but when I use df on it (at intervals of a few 
seconds), it seems that the _size_ of the filesystem is decreasing!  I 
might expect that the Used would go up (and Avail go down) if files were 
being created in the filesystem, but I certainly would not expect the 
actual size of the filesystem to change!


{149} /bin/df -k /tmp
Filesystem    1K-blocks       Used      Avail %Cap Mounted on
tmpfs         153689764         12  153689752   0% /tmp
{150} /bin/df -k /tmp
Filesystem    1K-blocks       Used      Avail %Cap Mounted on
tmpfs         153687740         12  153687728   0% /tmp
{151} /bin/df -k /tmp
Filesystem    1K-blocks       Used      Avail %Cap Mounted on
tmpfs         153687692         12  153687680   0% /tmp
{152} /bin/df -k /tmp
Filesystem    1K-blocks       Used      Avail %Cap Mounted on
tmpfs         153687284         12  153687272   0% /tmp
{153} /bin/df -k /tmp
Filesystem    1K-blocks       Used      Avail %Cap Mounted on
tmpfs         153687284         12  153687272   0% /tmp
{154} /bin/df -k /tmp
Filesystem    1K-blocks       Used      Avail %Cap Mounted on
tmpfs         153687012         12  153687000   0% /tmp
{155} /bin/df -k /tmp
Filesystem    1K-blocks       Used      Avail %Cap Mounted on
tmpfs         153687004         12  153686992   0% /tmp


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