- RHEL 7.9 x86-64
- high end dell servers with Xeon cpu's, 512gb ram, intel nic card
- I am the only user on the server(s), and there is no other work load on them
- cisco 1gbps wired LAN
- data.tar is ~ 50 gb
/bkup
is NFS mounted as vers=4.1 and sync- a
scp data.tar backupserver:/bkup/
runs at 112 MB/sec consistently; I've seen this for 5+ years and believe this to be correct - a
rsync -P data.tar /bkup
runs at 55 MB/sec consistently; this one is copying over NFS - running both the copies at the same time, scp drops from 112 to 55, and rsync over NFS drops from 55 to 35
- when one finishes, the other copy speed resumes to the original rate
why? and how can I improve speed over NFS?
scp
to the backupserver then a better use ofrsync
would be across the network rather than through NFS. In your scenariorsync
thinks it's copying local to local and switches off many of its optimisationsrsync -P
as an easy way to show copy speed. If I usecp
then I have to do math and look at my watch, but I'm still seeing half the speed of SSH. why?*sync
and[rw]size
? Have you triedasync
instead ofsync
?