[plug] rsync and nfs

Bernard Blackham bernard at blackham.com.au
Mon Oct 21 11:15:53 WST 2002


On Mon, Oct 21, 2002 at 09:26:23AM +0800, Mike Holland wrote:
> > 	mount /backups
> > 	rsync -avx --delete / /backups/machine/
> 
> Dont do this at home kids! Any kind of backup over NFS (or SMB) is going 
> to be much slower than than ftp/http/rcp/rsync speeds. And possibly less 
> reliable.

Really? Is that because of the overhead of NFS? There doesn't seem
to be a simple solution using ftp/http that will preserve
permissions, users, special files, etc. When I was using rsync over
rsh/ssh, the server didn't have enough memory to cope and spewed
this in the logs:

	Out of Memory: Killed process 6970 (rsync).
	VM: killing process rsync

leaving me with a half-done backup.

> > It appears to be somewhat faster though, or am I just hallucinating?
> 
> Odd. I would have expected it to checksum the files.

As Nick enlightened, it doesn't checksum on "local" files, including
NFS, so it really is faster. :)

> > When running it over ssh using -c blowfish, the server repeatedly
> > kills it's rsync process because it was hogging too much memory
> > (only has 32MB+80MB swap), so I just stuck to NFS. 
> 
> Well NFS certainly isnt secure, so why not try plain old rsh (the default 
> network protocol for rsync). Or put an rsync server on the remote host.

Though I'm generally paranoid, I'm not that fussed on my internal
network about security. Running an rsync server on the remote host
kills it, so NFS seems to be the simplest/most reliable method.

Alternately, could anybody who's used Coda please comment if it's
any more reliable than NFS? I've never used it but it claims to
support encryption too (for paranoia-demanding situations :)

Thanks,

Bernard.

-- 
 Bernard Blackham
 bernard at blackham.com.au
 Australian Linux Technical Conference 2003: http://www.linux.conf.au/



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