"Hmmmmm.... so the error message points to a space problem, but the behavior of the script points to a memory problem."

That reminds me of a Solaris 2.6 box where /var/tmp appeared to be memory mapped. Which was very awkward when a script ran amomk and logged the same old error message every few seconds. So we ran out of Swap rather than just ordinary disk space and all kinds of regular daemon processes died, we weren't even able to login anymore.

You may want to talk to your sysadmins abou this one...

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Cheers, Joe