Bitcoind Node crashes after using -dbcache option I've been trying to speed up my node sync by increasing the dbcache. However my node tends to crash overnight. My system is running ubuntu 18.04, 4GM of ram bitcoin core v0.18.

I've tried bitcoind -dbcache=4000, also tried setting it to 3000 and 2500. All have crashed overnight. 

Any thoughts on improving sync time using this or other methods?
You are allocating far too much dbcache. If you allocate 4000 MB to the dbcache, you will use up all of your RAM and it will crash. Your operating system needs RAM, Bitcoin Core itself needs RAM outside of the dbcache. I would highly recommend that you do not set a dbcache at all as 4 GB is really not enough RAM to handle a larger dbcache, Bitcoin Core's other RAM usage, operating system RAM usage, and whatever else may be running on your machine.

I suggest that you start Bitcoin Core without dbcache and check what your RAM usage is (using top or Ubuntu's system monitor). See how much RAM is being used and how much is free. Then you can set a higher dbcache if you have enough free.

Bitcoin Core has a few other suggestions for reducing memory usage. You can set maxmempool=&lt;n&gt; to a number less than the default 300. You can reduce the maximum number of connections by setting maxconnections=&lt;n&gt; to a number smaller than 125. Note that that only is helpful if you happen to have a lot of incoming connections. Lastly you can reduce the number of threads being used for signature validiation by using par=&lt;n&gt; and setting it to a number smaller than the number of cores your CPU has.