rsync: on remote machine: --drop-cache: unknown option

Matt McCutchen matt at
Sun Mar 13 17:06:30 MDT 2011

On Sun, 2011-03-13 at 17:52 -0500, will trillich wrote:
> Okay, are we CERTAIN there's no --drop-cache option in 3.0.7?

Yes.  By the way:

> sender-machine$ *rsync --version*
> rsync  version 3.0.7  protocol version 30
> Copyright (C) 1996-2009 by Andrew Tridgell, Wayne Davison, and others.
> Web site:
> Capabilities:
>     64-bit files, 64-bit inums, 64-bit timestamps, 64-bit long ints,
>     socketpairs, hardlinks, symlinks, IPv6, batchfiles, inplace,
>     append, ACLs, xattrs, iconv, no symtimes, A2

The "A2" there is not printed by any upstream version of rsync, so your
copy is definitely modified.

> So I'm not sure what to look at next.

Run your rsync command with -vv verbosity and look for an output line
that begins with "opening connection using:", which will show the remote
shell command used to invoke the server.  If that line contains
--drop-cache, blame the sending rsync.  Otherwise, run the command
manually.  If the same error occurs, the receiving machine is at fault
(maybe a badly designed ssh forced command).

> Is there an easy way to install version X.Y.Z of rsync on a debian
> system?

You can use a package management tool such as aptitude or install from
one of the source tarballs at .


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