I appreciate the reply - it keeps me from wondering "is there something I should be concerned about?". We use a co-location facility where we pay for bandwidth utilization so it's still an issue. ________________________________ From: CentOS <centos-bounces at centos.org> on behalf of Pete Biggs <pete at biggs.org.uk> Sent: Wednesday, March 25, 2020 1:32 PM To: centos at centos.org <centos at centos.org> Subject: [EXTERNAL] Re: [CentOS] Need help to fix bug in rsync Harriscomputer Leroy Tennison Network Information/Cyber Security Specialist E: leroy at datavoiceint.com [cid:Data-Voice-International-LOGO_aa3d1c6e-5cfb-451f-ba2c-af8059e69609.PNG] 2220 Bush Dr McKinney, Texas 75070 www.datavoiceint.com<http://www..com> This message has been sent on behalf of a company that is part of the Harris Operating Group of Constellation Software Inc. If you prefer not to be contacted by Harris Operating Group please notify us<http://subscribe.harriscomputer.com/>. This message is intended exclusively for the individual or entity to which it is addressed. This communication may contain information that is proprietary, privileged or confidential or otherwise legally exempt from disclosure. If you are not the named addressee, you are not authorized to read, print, retain, copy or disseminate this message or any part of it. If you have received this message in error, please notify the sender immediately by e-mail and delete all copies of the message. On Wed, 2020-03-25 at 19:15 +0100, Simon Matter via CentOS wrote: > > On Wed, 2020-03-25 at 14:39 +0000, Leroy Tennison wrote: > > > Since you state that using -z is almost always a bad idea, could you > > > provide the rationale for that? I must be missing something. > > > > > I think the "rationale" is that at some point the > > compression/decompression takes longer than the time reduction from > > sending a compressed file. It depends on the relative speeds of the > > machines and the network. > > > > You have most to gain from compressing large files, but if they are > > already compressed, then you have nothing to gain from just doing small > > files. > > > > It obviously depends on your network speed and if you have a metered > > connection, but does anyone really have such an ancient network > > connection still these days - I mean if you have fast enough machines > > at both ends to do rapid compression/decompression, it seems unlikely > > that you will have a damp piece of string connecting them. > > I really don't understand the discussion here. What is wrong with using -z > with rsync? We're using rsync with -z for backups and just don't want to > waste bandwidth for nothing. We have better use for our bandwidth and it > makes quite a difference when backing up terabytes of data. I don't really care if you use -z, but you asked for the rationale, and I gave you it. I'm not telling you what you should do. I'll try and make it simpler - if rsync takes 1 second to compress the file, then 1 second to decompress the file, and the whole transfer of the file takes 11 seconds uncompressed vs 10 seconds compressed, then dealing with file takes overall 12 seconds compressed, vs 11 seconds uncompressed. It's not worth it. But as I said it depends on your network and your machine speeds. It's up to you to decide what is best in your own situation. P. _______________________________________________ CentOS mailing list CentOS at centos.org https://lists.centos.org/mailman/listinfo/centos