Overview of Network Performance


 

Congested or Collision - resend

EtherNet

Latency

NFS

Slower remote server

Network Monitoring Tool

 

 

ping command


 

How to use ping

 

#> ping

 

How to read ping -s output

 

2 single SPARCstations on a quiet EtherNet always respond with less than 1 millisecond

 

Example of ping

 

#> ping -s host
PING host: 56 data bytes
64 bytes from host (1.1.1.1): icmp_seq=0. time7. ms
64 bytes from host (1.1.1.1): icmp_seq=0. time7. ms


----host PING Statistics----
5 packets transmitted, 5 packets received, 0% packet loss
round-trip (ms) min/avg/max = 1/2/7
 

 

spray command


 

How to use spray

 

#> spray

 

How to read spray output

 

If you use -d option, if there are many packet dropped the packet,

 

Example of spray

 

#> spray -d 20 -c 100 -l 2048 host

sending 100 packets of length 2048 to host ...
        no packets dropped by host
        560 packets/sec, 1147576 bytes/sec

 

netstat -i command


 

How to use netstat -i

 

#> netstat -i 5

 

How to read netstat data

 

collision percentage > 5% (one system)

collision percentage > 5% (all system)

errs field has data

 

Example of netstat

 

#> netstat -i 5
    input   le0      output         input  (Total)   output
packets errs packets errs colls packets errs packets errs colls
71853   1    27270   8    4839  72526   1    27943   8    4839
7       0    0       0    0     7       0    0       0    0   
14      0    0       0    0     14      0    0       0    0   

 

snoop command


 

How to use snoop

 

#> snoop

 

Example of snoop

 

#> snoop host1
#> snoop -o filename host1 host2
#> snoop -i filename -t r | more
#> snoop -i filename -p99,108
#> snoop -i filename -v -p101
#> snoop -i filename rpc nfs and host1 and host2

 

nfsstat -c command


 

How to use nfsstat -c

 

#> nfsstat -c

 

How to read nfsstat data

 

% of retrans of calls > 5% : maybe network problem

high badxid, as well as timeout : remote server slow

% of readlink of the calls > 10% : too many symbolic links

 

Example of nfsstat

 

#> nfsstat -c

Client rpc:
calls   badcalls retrans badxid timeout wait newcred timers
13185   0        8       0      8       0    0       50

Client nfs:
calls   badcalls nclget  nclcreate
13147   0        13147   0
null    getattr  setattr root   lookup   readlink read
0  0%   794  6%  10   0% 0  0%  2141 16% 2720 21% 6283 48%
wrcache write    create  remove rename   link     symlink
0  0%   581  4%  33   0% 29  0% 4  0%    0  0%    0  0%
mkdir   rmdir    readdir statf
0  0%   0  0%    539  4% 13 0%

 

 

Network Solutions


 

1st. Consider adding the Prestoserve NFS Write accelerator.

2nd. Subneting

3rd. Install the bridge

4st. Install the local disk into diskless machines.

 

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