Fedora27: NFS v4 terrible write performance, is async working

[Terry Barnaby]

When doing a tar -xzf ... of a big source tar on an NFSv4 file system 
the time taken is huge. I am seeing an overall data rate of about 1 
MByte per second across the network interface. If I copy a single large 
file I see a network data rate of about 110 MBytes/sec which is about 
the limit of the Gigabit Ethernet interface I am using.

Now, in the past I have used the NFS "async" mount option to help with 
write speed (lots of small files in the case of an untar of a set of 
source files).

However, this does not seem to speed this up in Fedora27 and also I 
don't see the "async" option listed when I run the "mount"
command. When 
I use the "sync" option it does show up in the "mount" list.

The question is, is the "async" option actually working with NFS v4 in 
Fedora27 ?

[Steven Whitehouse]

Hi,


On 28/01/18 07:48, Terry Barnaby wrote:
>  When doing a tar -xzf ... of a big source tar on an NFSv4 file system
>
>  the time taken is huge. I am seeing an overall data rate of about 1 
>  MByte per second across the network interface. If I copy a single 
>  large file I see a network data rate of about 110 MBytes/sec which is 
>  about the limit of the Gigabit Ethernet interface I am using.
>
>  Now, in the past I have used the NFS "async" mount option to help with 
>  write speed (lots of small files in the case of an untar of a set of 
>  source files).
>
>  However, this does not seem to speed this up in Fedora27 and also I 
>  don't see the "async" option listed when I run the "mount"
> command. 
>  When I use the "sync" option it does show up in the "mount" list.
>
>  The question is, is the "async" option actually working with NFS v4 in 
>  Fedora27 ?
>  _______________________________________________ 
What server is in use? Is that Linux too? Also, is this v4.0 or v4.1? 
I've copied in some of the NFS team who should be able to assist,

Steve.

[Terry Barnaby]

On 28/01/18 14:38, Steven Whitehouse wrote:
>  Hi,
>
>
>  On 28/01/18 07:48, Terry Barnaby wrote:
> > When doing a tar -xzf ... of a big source tar on an NFSv4 file system 
> > the time taken is huge. I am seeing an overall data rate of about 1 
> > MByte per second across the network interface. If I copy a single 
> > large file I see a network data rate of about 110 MBytes/sec which is 
> > about the limit of the Gigabit Ethernet interface I am using.
> >
> > Now, in the past I have used the NFS "async" mount option to help 
> > with write speed (lots of small files in the case of an untar of a 
> > set of source files).
> >
> > However, this does not seem to speed this up in Fedora27 and also I 
> > don't see the "async" option listed when I run the "mount"
> command. 
> > When I use the "sync" option it does show up in the "mount"
> list.
> >
> > The question is, is the "async" option actually working with NFS v4 
> > in Fedora27 ?
> > _______________________________________________
>
>  What server is in use? Is that Linux too? Also, is this v4.0 or v4.1? 
>  I've copied in some of the NFS team who should be able to assist,
>
>  Steve. 
Thanks for the reply.

Server is a Fedora27 as well. vers=4.2 the default. Same issue at other 
sites with Fedora27.

Server export: "/data *.kingnet(rw,async,fsid=17)"

Client fstab: "king.kingnet:/data /data nfs async,nocto 0 0"

Client mount: "king.kingnet:/data on /data type nfs4 
(rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,hard,nocto,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=192.168.202.2,local_lock=none,addr=192.168.202.1)"

[Richard W.M. Jones]

Please post questions on the users list:

https://lists.fedoraproject.org/admin/lists/users.lists.fedoraproject.org/

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-p2v converts physical machines to virtual machines.  Boot with a
live CD or over the network (PXE) and turn machines into KVM guests.
http://libguestfs.org/virt-v2v

[Terry Barnaby]

On 28/01/18 15:47, Richard W.M. Jones wrote:
>  Please post questions on the users list:
>
>  https://lists.fedoraproject.org/admin/lists/users.lists.fedoraproject.org/
>  
Sorry, will move there. Thought developers may be more into NFS that 
users in general these days there being no responses in the users list.

[Tomasz Kłoczko]

On 28 January 2018 at 07:48, Terry Barnaby <terry1(a)beam.ltd.uk&gt; wrote:

>  When doing a tar -xzf ... of a big source tar on an NFSv4 file system
> the
>  time taken is huge. I am seeing an overall data rate of about 1 MByte per
>  second across the network interface. If I copy a single large file I see a
>  network data rate of about 110 MBytes/sec which is about the limit of the
>  Gigabit Ethernet interface I am using.
>
>  Now, in the past I have used the NFS "async" mount option to help with
>  write speed (lots of small files in the case of an untar of a set of source
>  files).
>
>  However, this does not seem to speed this up in Fedora27 and also I don't
>  see the "async" option listed when I run the "mount" command. When I
> use
>  the "sync" option it does show up in the "mount" list.
>
>  The question is, is the "async" option actually working with NFS v4 in
>  Fedora27 ?
>  
Usually big NFS speed degradation is possible to observe when there is no
running rpcbind on the NFS client or communication whit this process is
blocked by FW.

kloczek
-- 
Tomasz Kłoczko | LinkedIn: http://lnkd.in/FXPWxH




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