Upgrade to 0.10.1: blockchain 0.9.3 compatible with 0.10.1?

[redPanda]

I have version 0.9.3 of bitcoind on my Ubuntu server and I want to upgrade to 0.10.1,
I have nothing in my wallet.
Does the blockchain 0.9.3 compatible with 0.10.1?
Do I have anything to keep from version 0.9.3 ?

[guitarplinker]

Unfortunately it looks like the 0.9.3 blockchain isn't compatible with the 0.10.1 release. See the following quote:

Because release 0.10.0 and later makes use of headers-first synchronization and
parallel block download (see further), the block files and databases are not
backwards-compatible with pre-0.10 versions of Bitcoin Core or other software:

However, in the 0.10.0 release, initial syncing was sped up a huge amount, so it should take less than 12 hours for your node to sync up again after updating.

[jonnybravo0311]

Unfortunately it looks like the 0.9.3 blockchain isn't compatible with the 0.10.1 release. See the following quote:

Because release 0.10.0 and later makes use of headers-first synchronization and
parallel block download (see further), the block files and databases are not
backwards-compatible with pre-0.10 versions of Bitcoin Core or other software:

However, in the 0.10.0 release, initial syncing was sped up a huge amount, so it should take less than 12 hours for your node to sync up again after updating.

I updated from 0.9.3 to 0.10.0 and then to 0.10.1 with no problems whatsoever.  I didn't have to re-download the blockchain, or anything like that at all.  I simply replaced my existing app with the newer version and everything kept right on trucking.

[guitarplinker]

I updated from 0.9.3 to 0.10.0 and then to 0.10.1 with no problems whatsoever.  I didn't have to re-download the blockchain, or anything like that at all.  I simply replaced my existing app with the newer version and everything kept right on trucking.

That makes sense. I misread his quote - I thought it meant that previous versions of the blockchain wouldn't be compatible with 0.10.1, but in reality what I think happens is that 0.10.1 condenses the blockchain into mainly headers (much smaller than whole blocks) making it incompatible if you try and downgrade afterwards.

So OP, you shouldn't need to redownload the blockchain again, however once you upgrade you can't easily downgrade again.

[redPanda]

OK, I will keep the existing blockchain (0.9.3) and upgrade bitcoind to 0.10.1
But I want to run a full node, will the new blocks be added with only the headers
or with all transactions?

[jonnybravo0311]

OK, I will keep the existing blockchain (0.9.3) and upgrade bitcoind to 0.10.1
But I want to run a full node, will the new blocks be added with only the headers
or with all transactions?

You get everything.  Output from my full node running on Ubuntu 14.04:

Code:

miner@devildog:~/bitcoin-0.10.1/src$ ./bitcoin-cli getblockcount
355398

Code:

miner@devildog:~/bitcoin-0.10.1/src$ ./bitcoin-cli getblockhash 355398
00000000000000000232164c96eaa6bf7cbc3dc61ea055840715b5a81ee8f6be

Code:

miner@devildog:~/bitcoin-0.10.1/src$ ./bitcoin-cli getblock 00000000000000000232164c96eaa6bf7cbc3dc61ea055840715b5a81ee8f6be
{
"hash" : "00000000000000000232164c96eaa6bf7cbc3dc61ea055840715b5a81ee8f6be",
"confirmations" : 1,
"size" : 539081,
"height" : 355398,
"version" : 2,
"merkleroot" : "346d4b1ac267fb311c371bef86fc051dcc1a37622cc7b9dc5488ec5b30b3235b",
"tx" : [
"f69f5593f3101b1266488399844ecf8f03289ee8b85f192cf38060364d1f1931",
"31a1d45fa64af4325678716f15a32778d2009cdfb14fbdec6202ede3cee42e98",
"73278ffafaf4e8914f0d89f271034077bc17aff06b86035730e00fcc11a2999f",
"efa1a15a29756e32d7441f0dcb35895652aaf08d22aaf7a1c242b1f0c03c7436",

...snipped a bunch out...

],
"time" : 1431019438,
"nonce" : 123860382,
"bits" : "181713dd",
"difficulty" : 47643398017.80344391,
"chainwork" : "00000000000000000000000000000000000000000006b47b99d84d8d47f3dd0b",
"previousblockhash" : "000000000000000002761482983864328320badf24d137101fab9a5861a59d30"
}

[redPanda]

Perfect! Thanks