Slow TCP/IP Performance

[seanasay]

Hi Guys

I have an old RS6000 7043 43P machine that we are having network performance problems!

The interface en0 is an RJ45 UTP connection on the back and performance is chronic. This is proven by the time taken to transfer files by ftp, etc.

I have been looking around for ways to check if the transmit mode is SIMPLEX, or DUPLEX etc but none of the commands seem to apply to this interface.

Where should I start. The network is a 100mb, an all other machines perform fine.

Help!
Sean

 

[mwallis]

Sean:

Try seting the network options:

tcp_sendspace
tcp_recvspace
udp_sendspace
udp_recvspace

The values of these options may help you. Issue the command:

no -a

and look for these parameters (I think the defaults are 16384 for these values. You can try increasing them:

no -o tcp_sendspace=32768

or

no -o tcp_sendpace=65536

and see if that helps preformance. Remember to do this for all four of the above mentioned options. If you have a problem, just take them back to the defaults.

Lotsa luck,
Mark

 

[nwardez]

Hi,

If your card is set as Auto_Negociate, IBM often recommands to set it as 100_Full_Duplex (if it's capable) instead (look in smitty - Communication - Network cards... I'm not at office and don't have good memory !)

You also need to reboot server to take effect.

May it can help.

 

[seanasay]

Hi

Still having problems!

The changes suggested above do net help. The performance is still 18K/s when ftping files.

I can see no way of enabling Full Duplex on the interface, as en0 does not support this parameter.

Help!

 

[MoshiachNow]

Hi,

Please post the results of :

1.lsattr -El ent0
2.errpt |head -20
3.measur the "rcp" timing of the same copy
4.what is the destination and source disk types ?
5.what is the size of the files you are copying ? "Long live king Moshiach !"
h

http://www.noahide.com/movement.htm

 

[seanasay]

You asked for ent0, but the machine is connected to the network by en0. The network is by and large 100BT, but this device is 10BT and the switches are operating at this speed, but not at full duplex. I cannot see anyway of setting it to full duplex either.

********************************************************

# lsattr -El en0
mtu 1500 Maximum IP Packet Size for This Device True
remmtu 1500 Maximum IP Packet Size for REMOTE Networks True
netaddr 198.115.59.118 Internet Address True
state up Current Interface Status True
arp on Address Resolution Protocol (ARP) True
netmask 255.255.255.0 Subnet Mask True
security none Security Level True
authority Authorized Users True
broadcast Broadcast Address True
netaddr6 N/A True
alias6 N/A True
prefixlen N/A True
alias4 N/A True
rfc1323 N/A True
tcp_nodelay N/A True
tcp_sendspace N/A True
tcp_recvspace N/A True
tcp_mssdflt N/A True

********************************************************

# lsattr -El ent0
busio 0x1000100 Bus I/O address False
busintr 6 Bus interrupt level False
intr_priority 3 Interrupt priority False
tx_que_size 64 TRANSMIT queue size True
rx_que_size 64 RECEIVE queue size True
full_duplex yes Full duplex True
use_alt_addr no Enable ALTERNATE ETHERNET address True
alt_addr 0x000000000000 ALTERNATE ETHERNET address True

********************************************************

# errpt |head -20
IDENTIFIER TIMESTAMP T C RESOURCE_NAME DESCRIPTION
2BFA76F6 1216131602 T S SYSPROC SYSTEM SHUTDOWN BY USER
9DBCFDEE 1216132302 T O errdemon ERROR LOGGING TURNED ON
192AC071 1216131502 T O errdemon ERROR LOGGING TURNED OFF
2BFA76F6 1208193602 T S SYSPROC SYSTEM SHUTDOWN BY USER
9DBCFDEE 1208193802 T O errdemon ERROR LOGGING TURNED ON
192AC071 1208193202 T O errdemon ERROR LOGGING TURNED OFF
E85C5C4C 1206163302 P S KBDDD SOFTWARE PROGRAM ERROR
2BFA76F6 1130085002 T S SYSPROC SYSTEM SHUTDOWN BY USER
9DBCFDEE 1130110602 T O errdemon ERROR LOGGING TURNED ON
192AC071 1130084802 T O errdemon ERROR LOGGING TURNED OFF
1104AA28 1118140802 T S SYSPROC SYSTEM RESET INTERRUPT RECEIVED
9DBCFDEE 1118141502 T O errdemon ERROR LOGGING TURNED ON
192AC071 1118140802 T O errdemon ERROR LOGGING TURNED OFF

********************************************************

rcp times out!

********************************************************

The file in question is 1mb but the same problem exists for all file sizes.

********************************************************

The AIX machine has a single 9Gb SCSI disk and is idle, and all machines FTPing to the machine are much faster.

********************************************************

 

[MoshiachNow]

Hi,

Your ent0 (this IS your physical level intrface,en0 is only a driver) is set to full duplex.

Is your switch set to the same ?
I suspect it's not,It could well explain this behaviour. "Long live king Moshiach !"
h

http://www.noahide.com/movement.htm

 

[seanasay]

Thanks levw!

The switch was set top autonegotiate, and this was the problem. Forcing it to 10BT FDx fixed the problem.

Thanks Again
Cheers
Sean

 

[ThJ]

Another clue:
Coming on a new site, I remember I got TCP/IP speed issues because /etc/hosts hadn't an entry for itself.

Thierry