I recently switched the system drive of my Mac Pro over to a SSD (which is possibly the best upgrade I've ever done) but started running into system disk space issues when exporting with compressor to a virtual cluster - which was odd since I set my virtual cluster to use storage on a scratch disk volume, not my system drive.
It turns out that for whatever reason QMaster was (is) completely ignoring my Shared Cluster Storage path and is just writing temp files to the default /var/spool/qmaster
I have no idea how long this was going on, since I had a pretty mammoth system drive before, so possibly just didn't notice. However, it's obviously a much bigger problem when you're trying to output >1TB worth of TIFF files through a tiny SSD!
I've tried all the usual solutions (wiping and reinstalling QMaster, making sure the custom storage path has no spaces in it, manually setting permissions) all with no luck.
As I just needed to get up and running ASAP I hacked together a workaround by creating a symbolic link at /var/spool/qmaster to point to my scratch location - which seems to work fine (and, oddly, seems to have accelerated my outputs a bit too, which is entirely bizarre)... but I'd love to see if anyone has any other bright ideas (or alternately, hopefully my symlink hack can help someone in a similar bind in the meantime).