>>>>> "Edward" == Edward Ned Harvey <[email protected]> writes:
>> From: [email protected] [mailto:[email protected]] On >> Behalf Of Tika Mahata >> >> I am looking for the solution to transfer large oracle database files Edward> about 2TB >> between two datacenters which have latency of 65ms with 1gpbs p2p link. >> What are the options to reduce the transfer time? I have Linux at both Edward> ends. >> Any software or protocol or tuning the OS parameters? Edward> The latency should be irrelevant for a continuous stream, but Edward> I find transfers over sftp for some reason are susceptible to Edward> the latency. Absolutely not. Read up on the Bandwidth Delay product. If you crank up your TCP window size on both ends, you can mitigate this, but TCP was never designed with large latencies and large bandwidth at the core algorithm levels. Edward> As long as you can use any other protocol - mbuffer, ftp, Edward> http, cifs/samba, nfs ... Presuming your connection is Edward> secured by some other means (such as vpn). Then even a single Edward> stream continuous transfer should saturate the link. Nope, once TCP gets to a certain number of outstanding packets, it pauses and waits for the acknowledgements to come back. So if you look at the traffic, you'll see a classic saw tooth performance graph. Edward> Also, you mentioned the data is oracle database. This should Edward> be irrelevant, as long as you stop the db server first. Then Edward> it's just a simple file transfer. Edward> Another thing. Being a database, it's probably compressible Edward> (depending on the data inside there). But being a 1Gbit link, Edward> you'll probably slow yourself down by running through gzip. Edward> Even gzip --fast isn't going to be fast enough. You might Edward> consider pigz --fast, or lzop. These should gain you some Edward> compression acceleration. It acutally might be smarter to just ship the redo logs over there instead too, but I'm not any type of Oracle expert. John _______________________________________________ bblisa mailing list [email protected] http://www.bblisa.org/mailman/listinfo/bblisa
