Re: Slow XFS write

[Martin LEUSCH <sce.tech@imereos.fr>]

Le 22/08/2018 à 15:17, Michael Stone a écrit :
> On Wed, Aug 22, 2018 at 02:25:51PM +0200, Martin LEUSCH wrote:
> > I tested write speed with dd command like "dd if=/dev/zero 
> > of=/var/srv/nfs/
> > testfile bs=1G count=1 oflag=direct".
> > The 10 MB/s for the data partition also correspond to the behavior I 
> > get in
> > real situation, when I copy a big file on NFS, 12GB are copied 
> > quickly then
> > hang for 15 or 20 minutes. When I copy big file with scp, It copy 
> > quickly the
> > at the beginning then decrease to 10 MB/s till the end.
>
> what happens with
> dd if=/dev/zero of=/var/srv/nfs/testfile bs=64k count=16k conv=fsync
>
> And this is direct on the server, not via NFS, right?
I've got same result as previous test.
tests with dd command are executed directly on the server.