I spent many hours this week-end trying to get the blockchain to sync in a linux vm on a mediocre windows PC. I failed numerous times due to memory shortages and i/o contention, but I finally managed to produce proof of work. If all goes well, I'll work my way through the queue and mine my first block since hardfork 16 in about 2 hours. This may be close to the minimum required configuration with the current hard fork and blockchain size. So, in case it will help anyone else, here's my configuration recipe.
Operating System: Windows 10
Hard Drives: C:\ and F:\
RAM: 12 G
CPU: 4 x I5-4570 (3.2GHZ)
Boot disk and page file: Stored on C:\
Oracle Virtual Box VM manager: Stored on drive C:\
Virtual box VM disk image: Ubuntu version 16.04.1 LTS stored on drive F:\
Virtual box swap: Stored on drive F:\
steemd executables: Stored on drive F:\
steemd file system size: 64G (source, binaries, and blockchain data - 20G used)
ubuntu VM RAM: 8G
ubuntu VM swap: 18G
/dev/shm: 16g (8.6G used, see this link for mounting instructions.)
Patched mining code: https://steemit.com/mining/@abit/steem-v0-16-0-brief-mining-guide
Compilation instructions: https://steemit.com/steemhelp/@joseph/mining-steem-for-dummies
Mining command: ./steemd --shared-file-dir /dev/shm --replay
Some reductions/consolidation may still be possible, but this is the first configuration that I was able to get working, so I thought I'd post it. I can't say it won't work with less resources, but I can say that if you configure it this way, it (probably) will.
Thank you very much to 
