File copying slow in network

[rick jones]

Starting from the "top" as it were I would:

1) run something like netperf TCP_STREAM (www.netperf.org) from Node1 to Node2 and then from Node2 to Node1 and see if they can achieve the same level of performance each way.

2) check netstat -s -p tcp statistics when transferring in each direction - take them on the sending side. snapshot from before the copy/netperf then snapshot from after and run them through beforeafter:

netstat -s -p tcp > before
netperf or filecopy
netstat -s -p tcp > after
beforeafter before after > delta

check delta for retransmissions. beforeafter comes from ftp://ftp.cup.hp.com/dist/networking/tools/

If there are retransmissions, do the aforementioned lanadmin checks - use lanadmin to check the link-level statistics for the NIC(s) in use for the transfers - look for packet drops, CRC errors, frame errors etc.

If there were retransmissions, but the lanadmin *statistics* (statistics, not configuration being the same...) are "clean" then check the statistics on the switch(es) between the nodes.

If there are routers, also check the stats on the routers.

If netperf performs well each way, but the backup does not, check the filesystem performance on each node (read and write) via your favorite tool(s).

[trilok_pvp]

Hi All,

I had checked the LAN settings for the all the unix servers, all rae same. I had done some testing, when i copy a file from NodeA to any of the Unix servers and Windows servers, it is copying fast. When i try the same from any of the other server to this NodeA, its getting delay. Its Transfers FAST, Only delay in getting the file.

[rick jones]

You keep saying "settings" and we keep asking about "statistics" which are different things. Just to be certain there is no translation confusion, could you post the statistics from lanadmin and netstat as described prior?

[trilok_pvp]

Hi rick,

I had taken a statics of the Lan and Lanadmin config. I had not found any obnormalities in the file.

can u pls suggest on this.

Because the hp openview backup is installed in the server NODEA. When i take backup of this server its works fine. The other Server it takes lot of time. 1MB file in 1Min time.

Pls find the attachemnet on details on lanadmin and statics

[trilok_pvp]

Hi

I check with my system admin, he informed that no issues in the port nor the speed (switch reports 100/full on the connection.

It may be with FTP service, is the FTP session inbound Active or Passive.

can you pls help on this

[rick jones]

beforeafter - ftp://ftp.cup.hp.com/dist/networking/tools/ is a very useful tool to subtract one set of netstat statistics from another...

Anyhow, look at the Node B before sending to Node A statistics. Notice the TCP retransmission stats:

4287 data packets (5990642 bytes) retransmitted

[rick jones]

beforeafter - ftp://ftp.cup.hp.com/dist/networking/tools/ is a very useful tool to subtract one set of netstat statistics from another...

Anyhow, look at the Node B before sending to Node A statistics. Notice the TCP retransmission stats:

4287 data packets (5990642 bytes) retransmitted
2087 retransmit timeouts

[Rita C Workman]

I may be way off on this one, but....

You mention the speed of 100/Full confirmed. But nowhere above do I see what the card is. On some older lancards we used to have when we were on 10.2, you had to set them to 100/Full Auto_OFF.

So, on the off chance that you are running some old lancard - could you tell us the card model number and the platform O/S you're running?

Thanks,
Rita

[rick jones]

well, twice I've tried to show the after stats, and twice they've been truncated. I've also tried to include how Node A is full duplex autoneg *off* and how unless the switch port is also autoneg off, that will lead to duplex mismatches.

lanadmin -g mibstats 0 should be run on node A to check the link-layer *statistics* and not just the settings - I suspect they will show errors. I suspect checking the switch port stats will also show errors. I won't attach my boilerplate on autoneg a third time :)

[Dennis Handly]

>rick: twice I've tried to show the after stats, and twice they've been truncated.

You're talking about the text in your reply and not the attachment? (You may need to go to the dark side and use a .txt suffix. Though I see your attachment fine.)