On 29/01/18 19:50, Steve Dickson wrote:
On 01/29/2018 12:42 PM, Steven Whitehouse wrote:
-------- Forwarded Message --------
Subject: Re: Fedora27: NFS v4 terrible write performance, is async working
Date: Sun, 28 Jan 2018 21:17:02 +0000
From: Terry Barnaby <terry1@xxxxxxxxxxx>
To: Steven Whitehouse <swhiteho@xxxxxxxxxx>, Development discussions related to Fedora <devel@xxxxxxxxxxxxxxxxxxxxxxx>, Terry Barnaby <terry1@xxxxxxxxxxx>
CC: Steve Dickson <steved@xxxxxxxxxx>, Benjamin Coddington <bcodding@xxxxxxxxxx>
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 ?
No. Its something left over from v3 that allowed servers to be unsafe.
With v4, the protocol defines stableness of the writes.
Thanks for the reply.
Ok, that's a shame unless NFSv4's write performance with small
files/dirs is relatively ok which it isn't on my systems.
Although async was "unsafe" this was not an issue in main standard
scenarios such as an NFS mounted home directory only being used by one
client.
The async option also does not appear to work when using NFSv3. I guess
it was removed from that protocol at some point as well ?
_______________________________________________
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)"
This looks normal except for setting fsid=17...
The best way to debug this is to open up a bugzilla report
and attached a (compressed) wireshark network trace to see
what is happening on the wire... The entire tar is not needed
just a good chunk...
steved.
Ok, will try doing the wireshark trace. What should I open a Bugzilla
report against, the kernel ?
What is the expected sort of write performance when un-taring, for
example, the linux kernel sources ? Is 2 MBytes/sec on average on a
Gigabit link typical (3 mins to untar 4.14.15) or should it be better ?
_______________________________________________
devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx
To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx
