topic Re: Copying between servers in Operating System - HP-UX

Copying between servers

Eli_pok — Tue, 02 Dec 2008 06:36:15 GMT

Hi,
I have 2 HPUX 11i machines, I'm trying to copy a 341 Mega file from one machine to another but, the rate I'm getting from the "secure" commands is absolutely lame ....
I'm coping on a 1 gigabit lan (intranet) both servers are 1000FD auto off (tried the auto on as well - same results).
ftp : 22 M/S - 15 Sec
Sftp : 7.6 M/s - 43 sec
rcp : refusing to work...
scp : 7.7 M/s - 42 sec
find | cpio : 24 M/s - 14 sec
tar : 14 M/s - 24 sec

Is there any way to make the secure command work faster ??

Re: Copying between servers

Jeeshan — Tue, 02 Dec 2008 07:09:25 GMT

huff, you have tried with all command!!!

for secure copy use "scp"

Re: Copying between servers

Ganesan R — Tue, 02 Dec 2008 07:18:32 GMT

Hi,

There are many things involved on this. Starting from disk IO read write, disk controller, system performance, network card, external network traffic, Gateways if any, etc...

It is not easy to pin point the resource making it delay. I personally feel the speed seems to be normal. Do you have any other server which is working faster to compart it with?

Re: Copying between servers

Fred Ruffet — Tue, 02 Dec 2008 07:33:56 GMT

If your problem is the difference between ftp and sftp/scp, it is absolutely normal. Remember that secured commands have to encrypt and decrypt data before and after transfer. It adds cpu time which is rather important. On big files it is significant.

Re: Copying between servers

Eli_pok — Tue, 02 Dec 2008 07:52:12 GMT

Tanks for your replies.
I agree with the CPU usage but it doesn't make any sense that the difference is of 15 M/s - up to 5 M/s would be acceptable.

I also tried it with dd and got the same results.

ps.
I've tried scp....

Re: Copying between servers

Bill Hassell — Tue, 02 Dec 2008 18:47:28 GMT

COmmands that are simple file copiers will indeed be quite lame (tar, cpio). Encrypt the data (scp, sftp) can be worse if you have a slow CPU. Only ftp will adapt to the speed of the network and grab the data using more efficient library calls. You can obtain very fast transfers between Gbit links by changing the MTU from 1500 to 9000 (called jumbo frames) *but* your network (switches) must support jumbo frames. Use lanadmin -M 9000 to change the MTU.

If you have a lot of files to copy, auto-port aggregation will give you even faster results. In several tests, I have taken 4 Gbit links using crossover cables (actually, Gbit will do the crossover automatically) and formed an aggregate where the bit rate if 4 Gbit and all the links are running jumbo frames. By starting 10 different ftp sessions, I measured multi-megabytes/sec using this type of link, rivaling the raw disk speed.

Re: Copying between servers

Ronald W. Widlewski — Wed, 03 Dec 2008 12:57:09 GMT

I only mention this option since I did
not notice "nfs" as a possibility.