I am trying to do a fast sync using
geth --fast but I am getting this message:
blockchain not empty, fast sync disabled
How can I empty the blockchain to allow for fast sync?
To remove your blockchain with geth, run:
--fast but you probably also need
--jitvm may also help). Without it, you are running with the default which is
A 50% speed increase is possible just by increasing the cache.
If you are starting from the beginning, use:
geth --fast --cache=1024 --jitvm
Depending on your RAM, you can also try with higher values, like
The number after
--cache= is the amount of memory allocated to the task of downloading the blockchain!!
Mac: ~/Library/Ethereum Linux: ~/.ethereum Windows: %APPDATA%/Ethereum
chaindata subdirectory that you find.
geth --fast --cache=1024 for a recommended way to sync the chain quickly (don't forget to use a bigger
--cache with a value like 1024, otherwise the default is 16, and it won't sync as quickly).
geth removedb is the simplest way to delete the blockchain in Geth.
If you have your blockchain partially or fully imported while starting
geth, then using the
--fast flag is ignored (the flag is disabled). To use the
--fast flag you have to remove all of the data from your
geth --fast --cache=2048
it seems at least Mac does not provide the other options under go1.9.2:
flag provided but not defined: -jitvm