What is the error and why is it triggered -"Got error 28 from storage engine" in MySQL

I was trying to run a query in MYSQL and the DB engine without execut开发者_如何学Going, returned me an error message as "Got error 28 from storage engine". What is its significance and y was it triggered...

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# perror 28
OS error code  28:  No space left on device

i.e. you've run out of disk space either in the main mysql data directory, or in the mysql tmp directory.