[CentOS] MySQL error 28, can't write temp files - how to debug?

[Alan Hodgson]

On Thursday 05 November 2009, Rudi Ahlers <Rudi at softdux.com> wrote:
> According to google search, errorcode 28 means the HDD is full. But it
> isn't:
>
>
> root at vps:[~]$ df -h
> Filesystem            Size  Used Avail Use% Mounted on
> /dev/sda1              84G   18G   62G  23% /
> none                  640M     0  640M   0% /dev/shm
> /usr/tmpDSK           485M   11M  449M   3% /tmp
>
>
> What else could cause this kind of problem?

You only have 449MB free on /tmp. It could easily fill that up during the 
query, and then delete the file before you run df again. Run it while the 
query is executing, I bet you see /tmp filling up.

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