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We're currently haveing an issue with one of our nginx servers. It's using an extreme amount of disk I/O.

It's the / (root - cciss/c0d0) partition that's being abused.

See picture of iotop here:

iostat: e

nginx is installed in /usr/local/nginx

Logging has been disabled (as far as i can see (cant find any logs being written to and i believe that all has been disabled in the conf files))

The files nginx servs (php files) is located on another harddrives/partition.

What is it that are creating this I/O? How can i find out which files / commands that are creating the I/O

Looking forward to hearing from you.


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Are you using nginx as a reverse proxy in front of an app server? If so, the disk IO is likely due to a lack of allocated upstream buffers in nginx (proxy, FastCGI, etc.).

Grep your nginx logs for "an upstream response is buffered to a temporary file" to be sure.

If reverse proxying:

If using FastCGI:,217034

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