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No blocks downloaded - MS Security Essentials users please read

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I got my friend to download and try Bitcoin out. I sent him one coin, but he hasn't received it. For some reason, his client isn't downloading any blocks. He turned on "Generate Coins" the minute he started the program for the first time. His speeds were in the 1400-1600 khash/s range, and he had 3 blocks. He generated 50 coins which will mature in another 100 blocks or so. He has around 40 connections.

To my knowledge, his coins will be invalid because none of the other nodes will accept his blocks. And, since he hasn't downloaded any blocks, he won't receive the one Bitcoin I sent him.

He uses Microsoft Security Essentials, but has added Bitcoin to its unblock list. He does have port 8333 open, but has a Linux network firewall. (He doesn't have the rights to access the firewall.)

What could be the problem?
Might need to have him start it with -addnode=x.x.x.x, where x.x.x.x is someone's static IP. Hopefully someone should be able to share theirs for that purpose... if that's the issue, of course. :-) I don't know for sure though.
This seems like a commonly reported problem now - something to do with the block downloading being really slow.  It may be related to the excessive amount of disk I/O that is generated during the initial download.  The database file is flushed to disk every time a block is added so this is being really slow for some people.  I think we can probably fix this up now that we know about it.. I for one didn't do much testing without having all the blocks, so it never occurred to me to try this under different systems.
The static IP using addnode will probably work.

However the software is designed to bootstrap using IRC.  Probably connecting out to the IRC server is being blocked either by Microsoft or his Linux firewall.  Without IRC his system is unable to discover other nodes.

IRC has nothing to do with port 8333, but most likely the Linux firewall is blocking incoming port 8333, so bitcoin will need to establish outgoing connections to other systems with a 8333 open for incoming connections.  Without opening incoming 8333 the max connections will be limited to 8 (I think).

Well, I don't have port 8333 open, but I was able to download all the blocks. (I don't use a firewall, though.)

I'll ask him to get rights to the firewall and check what it does with port 8333 connections. His port 8333 is open, but the firewall may be messing with it.
I think I read somewhere that if he has any connections, he is connecting to the IRC channel just fine... I think you're correct on the 8 connection limit without having port 8333 forwarded.

My thinking was that the static IP -addnode would help by providing a dedicated download source. If that still doesn't work well then I'd guess that laszlo has hit the nail on the head, and the constant full-rewrite of the file is to blame.
I think I read somewhere that if he has any connections, he is connecting to the IRC channel just fine... I think you're correct on the 8 connection limit without having port 8333 forwarded.

My thinking was that the static IP -addnode would help by providing a dedicated download source. If that still doesn't work well then I'd guess that laszlo has hit the nail on the head, and the constant full-rewrite of the file is to blame.

Oh, right.  Missed that he had 40 connections.   Huh

But 0 blocks downloaded?

My macmini is currently downloading blocks.  It is up to 38xxx after about 4 hours.  That is with two dedicated sources on the same lan plus another 6 it discovered out on the 'net.  (It is a 2009 model with 4gb of ram using only a 150GB partition of a 500GB, 7200rpm, 2.5" drive, running the 0.30 .zip'd version as a -server.)

The old macmini drive is in an atom D510 system and is a very slow hard disk.  It took a long time (18+hours) to download the blocks even with a dedicated source.  But even then it did not stay at 0 blocks for more than a minute or so.

I wonder how much downloading to a ramdisk would speed it up...
Maybe, the hdd is full?
Yea, possibly a full disk, or a failing disk... It's odd that even with a dedicated connection within your LAN it took that long to get that number of blocks. My 100 Mbps router funneled them from one of my PCs to another in less than 15 minutes, at the 65K+ blocks it needed.

Maybe a flakey router or internet connection? Might be worthwhile to do a speed test, or research Microsoft Security Essentials to make sure it's not toying with Bitcoin's ability to build the block list in some other way... not too familiar with Microsoft products I'm afraid.  Undecided
Okay, I solved the problem. The solution was in http://bitcointalk.org/index.php?topic=35.0.
So that was responsible for keeping blocks from downloading?

The link: "Win32 CPU Cycles vs 'Live Protection' Engines"

For BitcoinFX, Live Protection was keeping it from getting CPU for generating coins.  You said your friend was getting 1400-1600 khash/s, so it was getting CPU.  I guess Live Protection must have been blocking some other part of the program then?