Re: [bitcoin-dev] Why not archive the backend of Bitcoin blockchain?

From: ZmnSCPxj <ZmnSCPxj@protonmail•com>
To: アルム　カールヨハン <karl@dglab•com>,
	"Bitcoin Protocol Discussion"
	<bitcoin-dev@lists•linuxfoundation.org>
Cc: Segue <012mistery@frankentrikes•com>
Subject: Re: [bitcoin-dev] Why not archive the backend of Bitcoin blockchain?
Date: Thu, 10 May 2018 03:54:08 -0400	[thread overview]
Message-ID: <_6k3Kpt3N-IRVmNM9aZGd-8xDvIIkkhtvx5b6Tm_iMeM5McYwgNRCbO2Uerv2A7Bjpc84PQ35XPoexb9Oe-OgZ2tjW4733rVZ1L2mfnu-I8=@protonmail.com> (raw)
In-Reply-To: <CALJw2w5Ry9tS09O_BTD2-m6MxkE_prYpveAC1g1xC+1ofRWq_Q@mail.gmail.com>

Good morning karl and Segue,

Specifically for c-lightning, we are not yet rated for pruned bitcoind use, although if you installed and started running bitcoind before installing the lightningd, caught up to the chain, and then installed lightningd and set things up so that bitcoind will get killed if lightningd stops running (so that bitcoind will "never" leave lightningd too far behind).

Officially though pruned bitcoind is not supported for c-lightning, so loss of funds due to doing the above idea is entirely your fault.

On the topic of such a "chapter-based" archiving, it needs to get implemented and reviewed.  As-is I see no reason why it cannot be done, but I think the details are far more important.

1.  How do we select the archive servers?
2.  How can we ensure that no chapter has only a small number of actual owners who could easily coordinate to deny access to historical blockchain data to those they deem undesirable?

Regards,
ZmnSCPxj

‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐

On May 10, 2018 2:48 PM, アルム　カールヨハン via bitcoin-dev <bitcoin-dev@lists•linuxfoundation.org> wrote:

> He can use pruning to only store the last X MB of the blockchain. It
> 
> will store the UTXO set though, which is a couple of GBs. In total, a
> 
> pruned node with pruning set to 1000 MB ends up using 4.5 GB
> 
> currently, but it varies slightly due to the # of UTXOs in existence.
> 
> On Thu, May 10, 2018 at 9:56 AM, Segue via bitcoin-dev
> 
> bitcoin-dev@lists•linuxfoundation.org wrote:
> 
> > On 3/17/18, someone posted on the Lightning-dev list, "Can I try Lightning
> > 
> > without running a fully-fledged bitcoin block chain? (Yubin Ruan)." The
> > 
> > inquirer was asking because he didn't have much space to store the entire
> > 
> > blockchain on his laptop.
> > 
> > I replied:
> > 
> > "Developers,
> > 
> > On THIS note and slightly off-topic but relevant, why can't chunks of
> > 
> > blockchain peel off the backend periodically and be archived, say on minimum
> > 
> > of 150 computers across 7 continents?
> > 
> > It seems crazy to continue adding on to an increasingly long chain to
> > 
> > infinity if the old chapters (i.e. more than, say, 2 years old) could be
> > 
> > stored in an evenly distributed manner across the planet. The same 150
> > 
> > computers would not need to store every chapter either, just the index would
> > 
> > need to be widely distributed in order to reconnect with a chapter if
> > 
> > needed. Then maybe it is no longer a limitation in the future for people
> > 
> > like Yubin. "
> > 
> > It was suggested by a couple of lightning developers that I post this idea
> > 
> > on the bitcoin-dev list. So, here I post :).
> > 
> > Segue
> > 
> > bitcoin-dev mailing list
> > 
> > bitcoin-dev@lists•linuxfoundation.org
> > 
> > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
> 
> bitcoin-dev mailing list
> 
> bitcoin-dev@lists•linuxfoundation.org
> 
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev