Hello,
Recently while working with rsync as the way to mirror large (several GB) archive on a regular basis, I came across several problems, and also got the ideas about their possible solutions - please could you investigate & consider implementing the features, described below, to future RSYNC releases ? - when the checksumming (consider very large archive, several GB) stage of rsync runs slow (~3 and more minutes), which is the case of either slower CPU machines or machines with older HDDs that dont have UDMA or have just UDMA33 transfer modes, one can often observe that the network connection to the master site shuts down and the mirroring fails (in subsequent mirroring attempts, when, f.e., the archive is already transferred from about 90%). The reason why I think this happens, is the fact, that the bidirectionally-open connection is just reset by either client or server, becouse rsync does not do any transfer while the checksumming runs (I might be wrong, but this is what I observed), and the tcp connection is reset becouse of stall (I dont have clue by what means, becouse I'm no TCP/IP expert, but I suspect it might be just TCP/IP). How about adding a feature to keep the checksums in a berkeley-style database somewhere on the HDD separately, and with subsequent mirroring attempts, look to it just for the checksums, so that the rsync does not need to do checksumming of whole target (already mirrored) file tree ? I think implementing this could take some time, but it would certainly improve rsync's responsivenes and ease use with slow CPUs & HDDs - make output of error & status messages from rsync uniformed, so that it could be easily parsed by scripts (it is not right now - rsync 2.5.5) - perhaps if the network connection between rsync client and server stalls for some reason, implement something like 'tcp keepalive' feature ? I know these are suggestions only; I dont have enough power nor knowledges to implement them to rsync by myself (but I feel plagued myself with the problems described), so I'm sending these solution ideas to you in the hope they will be useful and could be implemented in the future. Please let me know your opinion about this. Thanks & regards, Jan -- To unsubscribe or change options: http://lists.samba.org/mailman/listinfo/rsync Before posting, read: http://www.tuxedo.org/~esr/faqs/smart-questions.html
