Learning exercise

[russL]

My grandson is trying to get started mining bitcoins using hardware attached to his gaming computer. He has no idea about security.
I've started a learning project by building bitcoin core 0.9.2 on a Udoo Quad with attached drive. My plan is to run as a GPU miner until he learns enough linux and security process', then get more hardware. Ultimately the Udoo would hide  behind the tv and run 24-7.

0.9.2 is very slow. It has been "synchronizing with the network" for 3 days now. CPU usage seems to average between 5% and 12%. It was built using the default setup.sh-configure-make-make install route.

Any idea why it is so slow?

Also any suggestions as to which hardware to use with the Udoo would be welcomed.

[Mikez]

You could download the blockchain via torrent: https://bitcoin.org/bin/blockchain/bootstrap.dat.torrent

[Wusolini]

Hi,

long time for wallet sync is standard. My first wallet take 2 days to sync.
Besides bootstrap there is option to use "lightweight" wallets e.g. Multibit.

[russL]

You could download the blockchain via torrent: https://bitcoin.org/bin/blockchain/bootstrap.dat.torrent

Thanks for the link. Right now it is showing between 6hrs and 2days to down load!
Once it is downloaded what do I do with it? This is to be a multi-user system and so far bitcoin-qt wants to download a copy for each user. Is there someway (perhaps links?) to insure only one copy is used?

[Mikez]

You can find out more details here, where someone asked something similar: https://bitcoin.stackexchange.com/questions/16769/how-to-use-the-bootstrap-dat-file-with-bitcoin-qt

[bitcoinforhelp]

just use multibit simple as that

[Chemistry1988]

Any idea why it is so slow?

The full blockchain data is over 21 GB as of today, and so it will take quite some time for you to download the data.

If you use bitcoin-qt to download it directly, the download speed would be depending on your peers' upload rate and so it would likely take much longer time to finish the initial sync compared with using the bootstrap torrent Mikez suggested.


You could also use some SPVs like Electrum and Multibit, which don't require you to have the full blockchain.

[Kprawn]

21Gb is huge - For first time download, with people capped internet at 20Gb per month. {Most 3rd world countries, still use capped internet}

Can it not be commpressed daily {Zip / Rar etc} and be placed on a fast P2P site?  {auto proccess} As a backup?

Rather than having to download the whole thing?

[Chemistry1988]

21Gb is huge - For first time download, with people capped internet at 20Gb per month. {Most 3rd world countries, still use capped internet}

Can it not be commpressed daily {Zip / Rar etc} and be placed on a fast P2P site?  {auto proccess} As a backup?

Rather than having to download the whole thing?

The reason not to update the bootstrap often is:

How often will this torrent be updated?

Assuming this project is deemed useful and worth continuing... the torrent will be updated once every few months, when the checkpoints are updated in the reference client source code.


Why not update the torrent more often?

A torrent works best when it is a large, static dataset that changes infrequently.  That maximizes the ability to seed the data, enabling even part-timer seeders to contribute meaningfully.  Less frequent changes also minimizes the risk that a malicious torrent will appear, with a long, malicious side chain.  The current policy only updates the torrent after blocks are buried many thousands deep in the chain.

Not sure about why it is not compressed, but I believe the devs want to keep the file simple.

Why should I trust you?

You don't have to:  This data is raw block chain data.  The client will verify this data during import.

Independent third parties may generate their own bootstrap.dat, up to height 295,000, and verify that the sha256sum matches that posted above.  The file format is simple and publicly known:

     <4-byte pchMessageStart><32-bit length><CBlock, serialized in network wire format>

Some people may be a bit uncomfortable opening a zip file.



Anyway, if you have limited bandwidth or limit HDD space, you shouldn't really use bitcoin-qt.

[russL]

21Gb is huge - For first time download, with people capped internet at 20Gb per month. {Most 3rd world countries, still use capped internet}

Can it not be commpressed daily {Zip / Rar etc} and be placed on a fast P2P site?  {auto proccess} As a backup?

Rather than having to download the whole thing?

Probably not. Compression only works on files that have lots of redundancy. For example, source code files (C, Python, etc) have lots of redundancy because some symbols are more common than others. Executable files have less redundancy and cannot be compressed as well. To be effective, bitcoin dat files should have low redundancy. Encryption techniques also reduce redundancy in files because redundancy provides clues to an attacker.

The real solution might be to find some way to collapse the older transactions into some sort of archive so we newbes don't have to down load more than a couple of years to be productive. If the archives were distributed over the internet they would be available everywhere as needed.

[Mikez]

Compression only works on files that have lots of redundancy. For example, source code files (C, Python, etc) have lots of redundancy because some symbols are more common than others. Executable files have less redundancy and cannot be compressed as well. To be effective, bitcoin dat files should have low redundancy. Encryption techniques also reduce redundancy in files because redundancy provides clues to an attacker.

I like the way you think Sir!
On the other hand, you could use Electrum or Multibit, as suggested above. They are thin clients and don't need to download the entire blockchain data.

[shorena]

21Gb is huge - For first time download, with people capped internet at 20Gb per month. {Most 3rd world countries, still use capped internet}

Can it not be commpressed daily {Zip / Rar etc} and be placed on a fast P2P site?  {auto proccess} As a backup?

Rather than having to download the whole thing?

Probably not. Compression only works on files that have lots of redundancy. For example, source code files (C, Python, etc) have lots of redundancy because some symbols are more common than others. Executable files have less redundancy and cannot be compressed as well. To be effective, bitcoin dat files should have low redundancy. Encryption techniques also reduce redundancy in files because redundancy provides clues to an attacker.

The real solution might be to find some way to collapse the older transactions into some sort of archive so we newbes don't have to down load more than a couple of years to be productive. If the archives were distributed over the internet they would be available everywhere as needed.

Nope, the solution is to read first. If you want to mine you dont need a full node. Just take mining software like cgminer and connect to a mining pool. Are you trying to soloming with a GPU here?
If you just want a wallet, take one of the light wallets, e.g. electrum or multibit.

If its a problem for you to download the blockchain, dont. There is no need unless you want to support the network or solo mine