I just ran into a problem now while I was patching one of my ESX 3.5 servers. I got this message from vCenter:

Insufficient disk space on datastore 'service console'

I SSH'ed into my ESX host and ran the df –ah command which came back with the following:

Apparently I had some big files sitting somewhere on the root partition, and I remembered at once that I was doing some throughput testing from my ESX to the FC SAN and iSCSI targets, so I knew where to go:

And here they are, two iso files consuming 3GB of my precious service console datastore:

Alternatively, you can run the find command with the following syntax to return the file size of your choice, sort them in human readable format and then write them in a text file (here it's larger than 300MB):

find / -type f -size +300000k -exec ls -lh {} \; 2> /dev/null | awk '{ print $NF ": " $5 }' | sort -nrk 2,2 > HyperViZor-FileSize.txt

ALWAYS Keep your Service Console FS clean!