Re: Kernel 2.6.15.1 + NFS is 4 times slower than FTP!?

From: Justin Piszcz
Date: Tue Jan 17 2006 - 14:02:03 EST


The file is 700MB.

Machine A (src) has 2GB of RAM / 2GB of swap
Machine B (dst) has 1GB of RAM / 2GB of swap.

Justin.

On Tue, 17 Jan 2006, Trond Myklebust wrote:

On Tue, 2006-01-17 at 13:55 -0500, Justin Piszcz wrote:
Did you get my other e-mail?

$ cp file /nfs/destination
$ lftp> put file


Yes, but how big a file is this? Is it significantly larger than the
amount of cache memory on the server? As I said, if ftp is failing to
sync the file to disk, then you may be comparing apples and oranges.

Cheers,
Trond

On Tue, 17 Jan 2006, Trond Myklebust wrote:

On Tue, 2006-01-17 at 13:38 -0500, Justin Piszcz wrote:
Writing from SRC(A) -> DST(B).
I have not tested reading, but as I recall there were similar speed issues
going the other way too, although I have not tested it recently.

How were you testing it? I'm not sure that ftp will actually sync your
file to disk (whereas that is pretty much mandatory for an NFS server),
so unless you are transferring very large files, you would expect to see
a speed difference due to caching of writes by the server.

Cheers,
Trond


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