Date: Thu, 10 May 2018 03:54:08 -0400
To: =?UTF-8?B?44Ki44Or44Og44CA44Kr44O844Or44Oo44OP44Oz?= <karl@dglab.com>,
	Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
From: ZmnSCPxj <ZmnSCPxj@protonmail.com>
Reply-To: ZmnSCPxj <ZmnSCPxj@protonmail.com>
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Cc: Segue <012mistery@frankentrikes.com>
Subject: Re: [bitcoin-dev] Why not archive the backend of Bitcoin blockchain?
Precedence: list

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 t=
he lightningd, caught up to the chain, and then installed lightningd and se=
t things up so that bitcoind will get killed if lightningd stops running (s=
o 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 implement=
ed 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 own=
ers who could easily coordinate to deny access to historical blockchain dat=
a to those they deem undesirable?

Regards,
ZmnSCPxj

=E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90 Original Me=
ssage =E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90

On May 10, 2018 2:48 PM, =E3=82=A2=E3=83=AB=E3=83=A0=E3=80=80=E3=82=AB=
=E3=83=BC=E3=83=AB=E3=83=A8=E3=83=8F=E3=83=B3 via bitcoin-dev <bitcoin-dev@=
lists.linuxfoundation.org> wrote:

> He can use pruning to only store the last X MB of the blockchain. It
>=20
> will store the UTXO set though, which is a couple of GBs. In total, a
>=20
> pruned node with pruning set to 1000 MB ends up using 4.5 GB
>=20
> currently, but it varies slightly due to the # of UTXOs in existence.
>=20
> On Thu, May 10, 2018 at 9:56 AM, Segue via bitcoin-dev
>=20
> bitcoin-dev@lists.linuxfoundation.org wrote:
>=20
> > On 3/17/18, someone posted on the Lightning-dev list, "Can I try Lightn=
ing
> >=20
> > without running a fully-fledged bitcoin block chain? (Yubin Ruan)." The
> >=20
> > inquirer was asking because he didn't have much space to store the enti=
re
> >=20
> > blockchain on his laptop.
> >=20
> > I replied:
> >=20
> > "Developers,
> >=20
> > On THIS note and slightly off-topic but relevant, why can't chunks of
> >=20
> > blockchain peel off the backend periodically and be archived, say on mi=
nimum
> >=20
> > of 150 computers across 7 continents?
> >=20
> > It seems crazy to continue adding on to an increasingly long chain to
> >=20
> > infinity if the old chapters (i.e. more than, say, 2 years old) could b=
e
> >=20
> > stored in an evenly distributed manner across the planet. The same 150
> >=20
> > computers would not need to store every chapter either, just the index =
would
> >=20
> > need to be widely distributed in order to reconnect with a chapter if
> >=20
> > needed. Then maybe it is no longer a limitation in the future for peopl=
e
> >=20
> > like Yubin. "
> >=20
> > It was suggested by a couple of lightning developers that I post this i=
dea
> >=20
> > on the bitcoin-dev list. So, here I post :).
> >=20
> > Segue
> >=20
> > bitcoin-dev mailing list
> >=20
> > bitcoin-dev@lists.linuxfoundation.org
> >=20
> > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>=20
> bitcoin-dev mailing list
>=20
> bitcoin-dev@lists.linuxfoundation.org
>=20
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev