20

Whenever I attempt to run geth on the command line, it seems to have trouble syncing with the blockchain. I am absolutely a novice so I could be completely overlooking. I am getting these warnings continuously(This is run on testnet):

WARN [04-21|17:40:40] Ancestor below allowance                 peer=20c9ad97c081d633 number=647267 hash=000000…000000 allowance=647267
WARN [04-21|17:40:40] Synchronisation failed, dropping peer    peer=20c9ad97c081d633 err="retrieved ancestor is invalid"

Please let me know if there is a solution for this. Thank you!

Improve this question
6
  • 1
    It's also important to note that this is on the testnet
    – user3376899
    Commented Apr 21, 2017 at 22:24
  • Which version of Geth are you running? How many peers do you see in the output of admin.peers()? (Don't really have any ideas on this... )
    – Richard Horrocks
    Commented Apr 24, 2017 at 20:35
  • 1.5.9 and where do I enter that command? The geth console? If so, I'm getting a 'peers' is not a function error
    – user3376899
    Commented Apr 24, 2017 at 22:37
  • I'm having exactly the same issue using geth v1.6.1-stable-021c3c28, deployed on Ubuntu on Microsoft Azure. Testnet, same as OP.
    – David Ammouial
    Commented May 9, 2017 at 7:18
  • In my case it happend because very old synchronization run long time ago. If it is your case, just delete all *.ldb files from ~/.ethereum/testnet/chaindata/ directory. Hope it will help.
    – user3024710
    Commented May 21, 2017 at 2:41

4 Answers 4

Reset to default
7

I received this error as well.

I deleted everything in the folder /Users/name/Library/Ethereum/testnet/geth/chaindata and then restarted with the command geth --testnet --fast and it started working

Improve this answer
2

Ethereum testnet has different versions, now the main testnet is called Ropsten. you can see all of the ongoing Ethereum testnets here: testnet.etherscan.io

It should be noted that Ropsten testnet was attacked in Feb/March 2017, which lead to a fork on the testnet to revive the network. More to read here: Ropsten Revival

To use the revived version, you need to remove the database and start resyncing using the revived nodes: Ropsten testnet PoW chain

Improve this answer
2

I did the following:

➜ ~ rm -rf ~/Library/Ethereum/testnet/geth/chaindata

Then:

➜ ~ geth --testnet --syncmode "fast" --rpc --rpcapi db,eth,net,web3,personal --cache=1024 --rpcport 8545 --rpcaddr 127.0.0.1 --rpccorsdomain "*"

And it should works

Improve this answer
1

I had this problem, where my chain was just perpetually ~90 blocks away from current. Restarting geth fixed it for me, luckily.

Improve this answer

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.