Re: [coLinux-users] NFS performance and colinux

[Nuno L. <lu...@nl...>]

192.168.1.1 is my router in the internal network, not the host OS.

colinux root # ping -s 4096 192.168.1.1
PING 192.168.1.1 (192.168.1.1) 4096(4124) bytes of data.
4104 bytes from 192.168.1.1: icmp_seq=3D1 ttl=3D64 time=3D4.50 ms
4104 bytes from 192.168.1.1: icmp_seq=3D2 ttl=3D64 time=3D3.53 ms
4104 bytes from 192.168.1.1: icmp_seq=3D3 ttl=3D64 time=3D3.48 ms
4104 bytes from 192.168.1.1: icmp_seq=3D4 ttl=3D64 time=3D4.11 ms
4104 bytes from 192.168.1.1: icmp_seq=3D5 ttl=3D64 time=3D3.61 ms
4104 bytes from 192.168.1.1: icmp_seq=3D6 ttl=3D64 time=3D3.33 ms
4104 bytes from 192.168.1.1: icmp_seq=3D7 ttl=3D64 time=3D3.72 ms
4104 bytes from 192.168.1.1: icmp_seq=3D8 ttl=3D64 time=3D3.44 ms
4104 bytes from 192.168.1.1: icmp_seq=3D9 ttl=3D64 time=3D3.36 ms
4104 bytes from 192.168.1.1: icmp_seq=3D10 ttl=3D64 time=3D3.63 ms
[....]
--- 192.168.1.1 ping statistics ---
120 packets transmitted, 120 received, 0% packet loss, time 120280ms
rtt min/avg/max/mdev =3D 3.280/3.761/9.236/0.951 ms

And a really remote host:

colinux root # ping -s 4096 www.colinux.org
PING www.colinux.org (66.35.250.210) 4096(4124) bytes of data.
4104 bytes from vhost.sourceforge.net (66.35.250.210): icmp_seq=3D1 ttl=3D=
45=20
time=3D599 ms
4104 bytes from vhost.sourceforge.net (66.35.250.210): icmp_seq=3D2 ttl=3D=
45=20
time=3D595 ms
4104 bytes from vhost.sourceforge.net (66.35.250.210): icmp_seq=3D3 ttl=3D=
45=20
time=3D595 ms
4104 bytes from vhost.sourceforge.net (66.35.250.210): icmp_seq=3D4 ttl=3D=
45=20
time=3D594 ms
4104 bytes from vhost.sourceforge.net (66.35.250.210): icmp_seq=3D5 ttl=3D=
45=20
time=3D596 ms
4104 bytes from vhost.sourceforge.net (66.35.250.210): icmp_seq=3D6 ttl=3D=
45=20
time=3D595 ms
4104 bytes from vhost.sourceforge.net (66.35.250.210): icmp_seq=3D7 ttl=3D=
45=20
time=3D595 ms
4104 bytes from vhost.sourceforge.net (66.35.250.210): icmp_seq=3D8 ttl=3D=
45=20
time=3D595 ms
4104 bytes from vhost.sourceforge.net (66.35.250.210): icmp_seq=3D9 ttl=3D=
45=20
time=3D625 ms
4104 bytes from vhost.sourceforge.net (66.35.250.210): icmp_seq=3D10=20
ttl=3D45 time=3D597 ms
[....]
--- www.colinux.org ping statistics ---
31 packets transmitted, 30 received, 3% packet loss, time 30386ms
rtt min/avg/max/mdev =3D 593.580/598.933/654.012/11.610 ms


I used a special build using the latest source, on a 2.6.8.1 kernel.

colinux root # uname -a
Linux colinux 2.6.8.1-co-0.6.2 #1 Sun Aug 15 04:33:48 WEST 2004 i686=20
Intel(R) Pentium(R) 4 CPU 1.70GHz GenuineIntel GNU/Linux


Regards,
~Nuno Lucas


Claude LeFrancois (QB/EMC), dando pulos de alegria, escreveu :
> Hi George,
>=20
> Thanks for your reply. I will give a try to the new release as soon as =
possible.
>=20
> However, I have made some NFS troubleshooting and I have finally been a=
ble to go a bit further with the jumpstart and I have been able to narrow=
 down the problem. The NFS performance problem seems to be produced by th=
e IP fragmentation.
>=20
> The default NFS block size on Linux is set to 4096 bytes (4K). When I s=
et the rootopts value to 1024, the jumpstart process goes a lot better. T=
his parameter set the rsize (read block size) option of the NFS mount req=
uest of the root filesystem coming from the jumpstart client. Unfortunate=
ly, all the other NFS mounted filesystems are not using this parameter an=
d suffer from the fragmentation problem. So, the jumpstart fails later.
>=20
> Basically, there is no fragmentation at 1024 but, at 4096, the fragment=
ation is very important. To verify that the fragmentation is responsible =
of the bad NFS performance, I have tested ping of 4K to a remote system f=
rom colinux:
>=20
> PING 142.133.81.2 (142.133.81.2) 4096(4124) bytes of data.
> 4104 bytes from 142.133.81.2: icmp_seq=3D9 ttl=3D255 time=3D82.4 ms
> 4104 bytes from 142.133.81.2: icmp_seq=3D14 ttl=3D255 time=3D4.17 ms
> 4104 bytes from 142.133.81.2: icmp_seq=3D22 ttl=3D255 time=3D4.04 ms
> 4104 bytes from 142.133.81.2: icmp_seq=3D24 ttl=3D255 time=3D5.05 ms
> 4104 bytes from 142.133.81.2: icmp_seq=3D25 ttl=3D255 time=3D4.15 ms
> 4104 bytes from 142.133.81.2: icmp_seq=3D32 ttl=3D255 time=3D21.0 ms
> 4104 bytes from 142.133.81.2: icmp_seq=3D34 ttl=3D255 time=3D4.16 ms
> 4104 bytes from 142.133.81.2: icmp_seq=3D78 ttl=3D255 time=3D4.17 ms
>=20
> --- 142.133.81.2 ping statistics ---
> 121 packets transmitted, 8 received, 93% packet loss, time 120805ms
> rtt min/avg/max/mdev =3D 4.048/16.165/82.463/25.656 ms, pipe 2
>=20
> The ping test shows the 93% of packet drops... It looks like the colinu=
x network adapter suffers from an IP fragmentation/reassembly performance=
 problem.
>=20
> Please, can you try the same ping on a later colinux version (ping -s 4=
096 <remote_ip_address>) if you have time and if you can ? So, we could a=
lready know if this problem is addressed with the new releases.
>=20
> Thanks,
>=20
> Claude LeFran=E7ois=20
> cla...@er...