Fast Downloads with Metalink
Reading the Slashdot thread about PC-BSD someone mentioned that there was a VMWare image pre-installed for playing around with it. On the download page, in addition to being able to select mirrors, as one expects with a large file, there was a Metalink. Not to be confused with Oracle’s worthless support website, Metalinks are files that describe methods for obtaining a file, in this case, HTTP and FTP locations where it is available and hashes for pieces of the file. After first trying a couple of mirrors and only getting ~60Kb/s I grabbed the Metalink file and installed Aria2, a command-line Metalink downloader. I simply pointed aria2 to the Metalink file (it can also take the URL of the Metalink) and it started downloading from 15 of the servers in the list simultaneously. Needless to say, this resulted in a much faster download. More information about Metalinks, including projects that employ them, can be found at the Metalink website.
VMWare images are so nice for just trying something out. PC-BSD is pretty cool too.
aria2 is a great downloader in general, besides supporting metalink. It does regular downloads as well as torrents, and uses minimal system resources.
Besides the usual speed of metalink downloads, the other nice things are convenience and automatic error correction. I occasionally get corrupted downloads over ftp/http, but if there’s a metalink available, and you use aria2, it can correct the downloads if there are chunk checksums in the metalink. repairing a small portion of a 600 meg download is so much better than having to restart it from scratch.
[Reply]
Comment by Ant Bryan — June 21, 2007 @ 6:27 pm