All my blocks has deleted

Question

I have a private network for testing. My problem is when ever I stop running geth network, all of my mined blocks are gone. I run like

geth --datadir "ethereum/node1" --port 30301 --networkid 1234 --rpc --rpcport "8545" --rpcapi db,eth,net,web3,personal --ws --wsport "8546" --rpccorsdomain "*"

(sometimes I use nohup) and I stop the server using cntrl+c. When geth is running I check block number using eth.blockNumber and it will show block number and it will increment. After I stop and start my server then I check using eth.blockNumber it always shows 0 and it takes some hour to mine blocks. Due to this, I'm lossing many of test data. Is this a common problem? Is there any work around to prevent this? Any idea will be helpful. Thank you.

Answer 1

you can use geth export <filename> and geth import <filename>

from Go Ethereum Wiki

Answer 2

sometimes I use nohup

What do you see when you tail the logs?

tail -f nohup.out

I suspect geth is just trying to determine current state corresponding to the highest block in your local node and shows block 0 until that is done.