From: Les M. <les...@gm...> - 2009-02-18 17:47:17
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John Goerzen wrote: > > First off, I gather that it keeps a hardlinked pool of data, so > whenever a file changes on any host, on the backup device, it will be > hardlinked to a file containing the same data, regardless of the host > it came from, right? > > So, given that, I don't really understand why there is a distinction > between a full and an incremental backup. Shouldn't either one take > up the same amount of space? That is, if you've got few changes on > the client, then on the server you're mostly just hardlinking things > anyway, right? So why is there a choice? With the tar and smb backup methods, full runs transfer everything from the remote, incrementals transfer only files with timestamps newer than the last full. With rsync, a full does a block checksum compare of all files, incrementals only files where the timestamp or length differ. On the server side, fulls rebuild a complete tree of links, incrementals only have the differing files. > Secondly, I gather that BackupPC mangles filenames. That doesn't > bother me, but how is it possible to use rsync in an efficient way > with that? rsync wouldn't be able to match up client-side filenames > with the server-side names since the server names are different, so it > wouldn't do its efficient transfers. Either that or you're having to > create temporary directory trees on the server, which sounds > inefficient. Or am I missing something? The server doesn't run the stock version of rsync. It has a perl version that understands the filename and compression conventions it uses for storage and can work with a stock rsync on the remote side. -- Les Mikesell les...@gm... |