Throttling rsync (curiosity question mostly)

[lightman47]

RHEL 8/9 and CentOS 7

I have backup scripts that utilize rsync. When I am running a backup it pretty much consumes my network connection, be it it wifi or sometimes even cat-5. I am wondering if there is a way to (within the script) 'throttle' rsync by like 10% or whatever? I'd just like it to not over-ride other programs also trying to use the connection.

I've looked into the rsync switches but didn't see anything obvious to me.

Thank you.

[TrevorH]

You mean like --bwlimit=RATE limit socket I/O bandwidth ?

[lightman47]

Thank you -- clearly I (again) got distracted while looking - I'm always "doing 18 things at a time".

[lightman47]

This works really great - UNTIL rsync reads the end of the file and then the cache begins emptying unrestricted. The result is back to a "hung" network until the cache empties.

Without turning off write-caching entirely, can I somehow 'adjust' it? I looked at https://linuxconfig.org/improve-hard-dr ... ck-caching

Thanks

[TrevorH]

You could try playing with the various sysctls like these ones:

vm.dirty_writeback_centisecs = 200
vm.dirty_ratio = 15
vm.dirty_background_ratio = 3
vm.dirty_expire_centisecs = 500
vm.swappiness = 3
vm.vfs_cache_pressure = 170