> I never did track down this exact issue but it's an artificial > slowdown.. meaning compression and whatever else wouldn't help much.
I meant for anyone who wanted to distribute the dataset as a project. > It has something to do with the database file locking and flushing.. > on some systems I've seen the block chain get fully done in 10-20 > mins and on others it slows down to the point where it will never > catch up.. but not in a way that's related to the age of the computer > or anything. You might want to experiment if you want to track this > down.. try building your own libs Rather than use dated/modified packages, I compiled current versions of all component sources manually. > and compare different operating > systems, on the same hardware to get a more 'true' comparison maybe. True. Used them all before, happy with BSD for now. Just knowing what the general setup is on those zippy systems should suffice. ie: blindly fishing for such a zippy system to compare through various install tests doesn't sound too appealing. It's different than benchmarking. Datapoint: The system below is not zippy. > I think everyone is vaguely aware of the problem but it has not > been tracked down and eliminated. I don't think the problem is > within bitcoin itself but in how truthfully the database file is > actually written to disk. Am I correct in guessing that, given a certain height, the data in blkindex and blk0001 should be the same across instances? # file blk* blk0001.dat: data blkindex.dat: Berkeley DB (Btree, version 9, native byte-order) Pursuant to comparison, what is the format of blk0001.dat? > If it really gets flushed to disk every > block like bitcoin wants it to be, then there is no way that you > could get more than 50-60 blocks per second through it (due to > rotational latency), but on some operating systems and versions/options > it seems to end up caching the writes and flies through it at > thousands of blocks per second. The problem is similar to what's > mentioned here: http://www.sqlite.org/faq.html#q19 I'm not running Linux with asynchronous data and metadata turned on by default if that's what you mean :) ZFS, disk crypto, standard drive write cache. Looking at it, I'm largely buried in that crypto at 8MB/sec or so. > Perhaps it's as simple as some default in the db lib.. and it seems > to default to different things on different version/operating > systems/filesystems. Hmm, I compiled everything with the defaults. Will go back and look at bdb options. I don't think there was anything interesting there. I'd bet a lot is tied to the fs and cpu. Single core p4@1.8 512k/2g isn't much up against ZFS+disk crypto. It seems to take its time and roll up all but the last database file (of a hundred or more) on receiving sigterm. Is it supposed to roll and delete the last log too? Can I safely delete everything but the blk* files? (wallet excepted of course :) Currently, in KiB... running: 853716 database 747881 blk0001.dat 290601 blkindex.dat 4361 addr.dat 137 __db.005 137 __db.004 137 __db.003 137 __db.002 41 __db.006 25 __db.001 sigterm: 750569 blk0001.dat 291497 blkindex.dat 8465 database/log.0000000nnn 4361 addr.dat database/log.0000000133: Berkeley DB (Log, version 16, native byte-order) ------------------------------------------------------------------------------ Keep Your Developer Skills Current with LearnDevNow! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-d2d _______________________________________________ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
