When I run gunzip on a 1.7GB file (which generates an 8GB file) on an EBS volume, pdflush freezes after gunzip runs and the CPU hangs indefinitely at 100% IO Wait. Here's the output from 'ps aux | grep pdflush'. Note the D status
root 87 0.0 0.0 0 0 ? D 06:18 0:00 pdflush root 88 0.0 0.0 0 0 ? D 06:18 0:00 pdflush
The only solution is to kill the pdflush processes. The processes don't die immediately either.
This problem is repeatable and happens with new instances. I'm running 2xlarge instances and I have way more RAM free than is being used (i.e. /proc/meminfo shows 20+GB MemFree)
Has anyone found a workaround to this problem in the past?
Thanks for any thoughts.