large rsync runs stall system perfomance (missing --drop-cache)

[ceg]

Please build the package with the --drop-cache patch that is available in the tarball, to avoid filling up the io cache with not re-queried copied data. The current behavior pushes the data of other process out of the cache and thus slows them down.

http://insights.oetiker.ch/linux/fadvise.html

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Sergey Tryuber (stryuber)]

As an ugly workaroundt you could use rsync together with nocache (https://github.com/Feh/nocache). Worked for us.

[Sergey Tryuber (stryuber)]

rsync + nocache worked only on the side which transfers data, not only receiver side. We eventually had to apply patch (http://insights.oetiker.ch/linux/fadvise.html)

[Wayne Davison (wayned)]

It can easily work on both sides. e.g.:

nocache rsync -aiv --rsync-path='nocache rsync' /src/ host:/dest/

The --rsync-path option tells the remote side it should also use nocache wrapper.

[Rolf Leggewie (r0lf)]

This should be pushed upstream. It will then get into Ubuntu automatically.