Ropsten Testnet – Are There Any Bootnodes for the Revived Ropsten Testnet?

I think you are looking for something like this.

geth --testnet --fast --bootnodes "enode://20c9ad97c081d63397d7b685a412227a40e23c8bdc6688c6f37e97cfbc22d2b4d1db1510d8f61e6a8866ad7f0e17c02b14182d37ea7c3c8b9c2683aeb6b733a1@52.169.14.227:30303,enode://6ce05930c72abc632c58e2e4324f7c7ea478cec0ed4fa2528982cf34483094e9cbc9216e7aa349691242576d552a2a56aaeae426c5303ded677ce455ba1acd9d@13.84.180.240:30303"

In short, when node is syncing it executes transactions, that are program code, that needs to read and write data (variables, arrays etc.), when executes. The data is stored at disk, and read\write accesses are random in general (depens of what code transactions include). As bigger blockchain, as more area to perform random reads\writes. I'm not sure, but I think make syncing slower when blockchain growing. So the first problem of syncing is IO. When I was syncing my node I had about 1.2K read and 0.15K write operations per second in average (SSD). I tryed to use HDD first, but syncing was too slow and I read that many people could not sync their nodes at all with HDD. The problem for me was that in production I have only HDD.

I've solved my problem with two steps:

1. I made synchronization with good hardware (big SSD, good CPU)
2. I copied blockchain directory to target host with HDD.
3. Profit

P.S. I can not say anything abot RAM beacause I have 32GB and did not monitor it. You can give more info about RAM usage by geth process and by docker.