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Bitcoin => Bitcoin Technical Support => Topic started by: dragospirvu75 on February 28, 2022, 11:18:08 AM



Title: Bitcoin Core Sync / Download way too slow
Post by: dragospirvu75 on February 28, 2022, 11:18:08 AM
Guys, I will try and be to the point. I know other people had the same issue, but maybe you have an idea specific for me. I want to volunteer for running a full node. But sync takes way too long. Changed the size of database cache to 1024 mb. I tested my internet speed, it's 430 Mbps, I have windows 10, 4GB Ram and Intel I3. I've been letting it to download 8h/day for 2 weeks (~110h) and it downloaded only 20%.  Progress increase per hour is generally 0.01-0.08%. It has reached its peak 0.30-0.50% but for a very short of time. I can't wait 24-48 weeks to download it all. Do you have any ideas for me? Thanks!


Title: Re: Bitcoin Core Sync / Download way too slow
Post by: nc50lc on February 28, 2022, 11:36:03 AM
That's indeed slow considering the internet speed and it's a quite capable machine.
However, the most important factor to the initial block download's speed is the Drive which you haven't mentioned.
So, are you using an HDD/SSD, internal or external?

It can also be affected by your connection to the network, How many peers do you have in "Window->Peers"?


Title: Re: Bitcoin Core Sync / Download way too slow
Post by: dragospirvu75 on February 28, 2022, 11:48:25 AM
Thank you for your fast answer. I have a 1TB HDD in my pc, don't know if it's internal or external, too technical for me. Right now I have 5 peers at 0.07%, an hour ago I had 3 peers at 0.01%. Don't know how many peers I had at 0.30-0.50%


Title: Re: Bitcoin Core Sync / Download way too slow
Post by: dragospirvu75 on February 28, 2022, 11:56:21 AM
Forgot to mention, I have 256GB SSD (where is installed the windows and some small apps) and 1TB HDD where I have 800 GB for Bitcoin Core.


Title: Re: Bitcoin Core Sync / Download way too slow
Post by: nc50lc on February 28, 2022, 11:56:40 AM
"Internal" means that the HDD is inside the PC, while "External" is connected via USB or other external ports.

Right now I have 5 peers at 0.07%, an hour ago I had 3 peers at 0.01%. Don't know how many peers I had at 0.30-0.50%
That's quite a low number of peers but 5 shouldn't be limiting the speed to 0.07%/hr so it must be the HDD or something else.
What I'm thinking is your RAM must not be enough for the dbcache that you've set together with the background processes of Windows10
That will use a lot of "page files" which will further stress your HDD.

Try to reduce your database cache into 512 instead (or lower); then, restart Bitcoin Core and check if it'll improve.


Title: Re: Bitcoin Core Sync / Download way too slow
Post by: NeuroticFish on February 28, 2022, 12:00:35 PM
Forgot to mention, I have 256GB SSD (where is installed the windows and some small apps) and 1TB HDD where I have 800 GB for Bitcoin Core.

Use Symbolic links and put the chainstate (and indexes too if you have) onto SSD. You can move them back after the initial sync has reached 100%.
Of course, these operations need Bitcoin Core not be running when you do that.


Title: Re: Bitcoin Core Sync / Download way too slow
Post by: dragospirvu75 on February 28, 2022, 12:35:25 PM
For nc50lc:
Then they must be internal. I've changed database cache to 400 and 512. Insignificant upgrade (+0.01% at the same number of peers when I had 1024). For the last 10 minutes it syncs at 0.02% with 2 peers.

For NeuroticFish:
I don't know what are Symbolic links, chainstate or indexes, I'm new to Bitcoin Core, I had used online wallets and now hardware wallet (trezor). I will search on Google, hope to find something useful and make the change you said.

Thank you guys for your support, I will come back with updates.

Meanwhile, if someone has other opinions, let them here. Ty.


Title: Re: Bitcoin Core Sync / Download way too slow
Post by: NeuroticFish on February 28, 2022, 12:40:45 PM
I don't know what are Symbolic links, chainstate or indexes, I'm new to Bitcoin Core, I had used online wallets and now hardware wallet (trezor). I will search on Google, hope to find something useful and make the change you said.

Symbolic links are some sort of shortcuts. You put a shortcut in a folder telling that the date is somewhere else. The system will see the data like it's in the original place.
A google result that could explain it better is: https://www.howtogeek.com/howto/16226/complete-guide-to-symbolic-links-symlinks-on-windows-or-linux/

chainstate or indexes are 2 subfolders of your (Bitcoin Core's) data folder. My point was to move the current content of those folders to the SSD and put (on the HDD) symbolic links to point to the new location.

When I've done that myself the speed improvement was significant.

At the end, if you want to have all the data on HDD and move the content back, you'll have to pay attention at removing the symbolic links (you may have to google a little).


Title: Re: Bitcoin Core Sync / Download way too slow
Post by: NotATether on February 28, 2022, 12:41:08 PM
The problem is that you have way too few peers to sync at a normal speed. Peers should have been accumulating inside your peers.dat file.

I could try PMing you my peers.dat contents which you can paste inside yours (I have a few dozen peers on my node but the list is several weeks old), then restart Core to be able to connect to them or if they slowly start disconnecting one by one.


Title: Re: Bitcoin Core Sync / Download way too slow
Post by: dragospirvu75 on February 28, 2022, 12:57:53 PM
Thank NeuroticFish for your enlightening answer. I found the chainstate folder (don't have indexes folder). I will make your change.
NotATether, please PM me you peers.dat, I will see how NeuroticFish's solution works and then put your file.

Thanks to everyone for your time and answers to help me. I will tip you with a burger on your addresses :)


Title: Re: Bitcoin Core Sync / Download way too slow
Post by: nc50lc on February 28, 2022, 05:27:53 PM
For nc50lc:
Then they must be internal. I've changed database cache to 400 and 512. Insignificant upgrade (+0.01% at the same number of peers when I had 1024). For the last 10 minutes it syncs at 0.02% with 2 peers.
Forgot to mention, I have 256GB SSD (where is installed the windows and some small apps) and 1TB HDD where I have 800 GB for Bitcoin Core.
I missed this reply (posted 19sec before mine).
Then limiting your dbcache to reduce the 'page file' wont really do much because the data directory isn't in the same drive where the 'page file' will be.


Title: Re: Bitcoin Core Sync / Download way too slow
Post by: dragospirvu75 on February 28, 2022, 06:32:04 PM
I suspected you didn't see it. Anyway, thanks for your idea!


Title: Re: Bitcoin Core Sync / Download way too slow
Post by: dragospirvu75 on March 01, 2022, 04:25:25 PM
Message for everyone who has this problem (Downloading blockchain too slow). I tried NeuroticFish's method and it WORKED (Moved chainstate folder from HDD to SSD and made a symbolic link with the help of the link he sent, with command prompt). A huge progress from 0.02-0.10% to 3% (and it's still going up). Thank you for your marvellous solution and all others who tried to help me. Wish you best luck, guys!


Title: Re: Bitcoin Core Sync / Download way too slow
Post by: NeuroticFish on March 01, 2022, 06:46:15 PM
Thanks for the feedback, I'm glad it worked.
(And thanks for the tip too if it was from you. :))


Title: Re: Bitcoin Core Sync / Download way too slow
Post by: nc50lc on March 02, 2022, 02:48:50 AM
Message for everyone who has this problem (Downloading blockchain too slow). I tried NeuroticFish's method and it WORKED (Moved chainstate folder from HDD to SSD and made a symbolic link with the help of the link he sent, with command prompt). -snip-
Or they can use -blocksdir as a start parameter or in the config file (for those who can't/wont use symlink).
That will basically do the same, Bitcoin will use the default data directory for the chainstate and other data except the blockchain which will be saved in the specified blocks directory.

https://github.com/bitcoin/bitcoin/blob/master/src/init.cpp#L401 (https://github.com/bitcoin/bitcoin/blob/master/src/init.cpp#L401)


Title: Re: Bitcoin Core Sync / Download way too slow
Post by: dragospirvu75 on March 02, 2022, 12:03:48 PM
Yeah, or this method. I tipped all of you with $1 (or maybe a little more with fee?!). Take care! :)