What should I do to increase bitcoind sync speed?
First, make sure you have listen=1 in your bitcoin.conf file, and that the P2P port is open on your VPS so that it can make more than 8 connections.

Then you'll want to make sure you have a high disk speed or IO specified (definitely not HDD - I have a feeling you meant SSD). The faster the SSD the better. 2GB RAM should be fine, but you may want to up it to 4GB and 4 CPUs, at least while syncing. bitcoind will use the most resources while syncing, then you can downgrade once it's synced.