topic Re: rlogin to linux box slow in Operating System - Linux

rlogin to linux box slow

jane zhang — Fri, 27 May 2005 17:02:59 GMT

Hello all,

I have linux WS v3 installed on the same model of DELL PCs. Those linux share the same NIS/NFS/automount setup.

rlogin to one box is obviously much slower than the rest of the boxes.

Any ideas?

Thanks,

Jane

Re: rlogin to linux box slow

Stuart Browne — Fri, 27 May 2005 18:18:56 GMT

I'd be checking hosts files, and DNS servers.

In any case, I'm assuming this is in a protected network setup which is why you're using 'rlogin' instead of 'ssh' ?

Re: rlogin to linux box slow

jane zhang — Fri, 27 May 2005 18:23:45 GMT

Thanks for the reply.

they have the same /etc/resolv.conf and /etc/hosts ( except for the ip addess in this file).

Jane

Re: rlogin to linux box slow

Stuart Browne — Fri, 27 May 2005 18:30:11 GMT

Does the IP address of this workstation resolve forwards and backwards?

What entries are in '/var/log/messages' and '/var/log/secure' during an 'rlogin' attempt?

What user are you going too/from when using 'rlogin'?

Have you got a 'tcpdump' of the TCP conversation?

Re: rlogin to linux box slow

Bejoy C Alias — Sat, 28 May 2005 02:52:05 GMT

Can u tell the exact problem, i mean r u facing the slow down while loging in or after loging in or while working after rlogin ?

Re: rlogin to linux box slow

Gopi Sekar — Sat, 28 May 2005 03:47:59 GMT

check the routing information from that particular box.

run 'route' command as root and see whether it outputs the routing information immediately or it takes a while to complete. if it takes a while to complete then its more likely that something wrong with your name server and router configuration.

This problem also happens when the server is configured to do reverse lookup and does not have proper nameserver and routing information configured

Regards,
Gopi

Re: rlogin to linux box slow

jane zhang — Tue, 31 May 2005 13:11:22 GMT

Thanks for all the replies.

The situration is that I ( janez not root ) rlogin from one box in the same NIS to della07 and della06. della07( the slow one)always take 10sec to give me back the prompt while della06 came back immediately.

route command come back quickly on both.

From /var/log/secure of two boxes.

May 31 10:20:07 della07 xinetd[5076]: START: shell pid=20041 from=xxx.xx.xxx.xxx

May 31 12:29:13 della06 xinetd[5860]: START: login pid=5194 from=xxx.xx.xxx.xxx

my user run his simulation on those two machines, della06 finished the job 34 hrs while della07 finished the job 46 hrs.

The machines belong to same model with same memory and swap space and OS and kernel.

Thanks,

Jane

Re: rlogin to linux box slow

xyko_1 — Tue, 31 May 2005 13:49:12 GMT

Hi Jane,

all machines are in the same subnet ?

If you run traceroute from source machine to the target ones you have the same number of hops ? The paths are all correct ?

One more thing. Did you verify if there is network errors between the source and the slow target machine ? Did you see if the NIC is configured with the right speed (look the switch port also).

Hope it helps.
Xyko

Re: rlogin to linux box slow

Maxim Rozin — Tue, 31 May 2005 14:57:10 GMT

Hi Jane,

What is the actual network speed on these machines?
Send a big file (~10MB) from a third machine, to each one of these two, using FTP (or SFTP). After the file transfer completes, the average transfer speed will be printed.

What is the network speed in your LAN (10/100/1000)?

Max.

Re: rlogin to linux box slow

jane zhang — Tue, 31 May 2005 15:56:16 GMT

Hi all,

della06, della07 are in the same subnet. dcssun42 is the box I rlogin to the 2 linux boxes.

janez@dcssun42: /usr/sbin/traceroute della06
traceroute to della06 30 hops max, 40 byte packets
1 della06 1.795 ms 0.182 ms 0.177 ms janez@dcssun42: /usr/sbin/traceroute della07
traceroute to della07 30 hops max, 40 byte packets
1 della07 0.315 ms 0.213 ms 0.306 ms

The result also shows della07 is slower.

Would you let me know how to check the speed of the network, I used landiag in hp but not sure in linux.

Thanks,

Jane

Re: rlogin to linux box slow

jane zhang — Tue, 31 May 2005 16:52:35 GMT

From dmesg of both boxes :

bcm5700: eth0 NIC Link is UP, 100 Mbps full duplex

Jane

Re: rlogin to linux box slow

Stuart Browne — Tue, 31 May 2005 17:35:19 GMT

12 hour difference in processing the same task, on identical hardware?

I'd be looking for processes running on that node of which aren't running on other nodes.

I'd also check the BIOS cache settings as well.

Re: rlogin to linux box slow

xyko_1 — Wed, 01 Jun 2005 09:09:49 GMT

Hi Jane,

did you see if there are network errors ?
ifconfig will show you that.

You may also see if there are some warning or error messages on /var/log/messages during the process time of your long running job.

Verify also if memory is not a constraint in the slowest machine. free will help you on it.

If possible run top on both machines during the long running job, to see if another big consumming process appears on the slowest one that don't appears on the other one.

Good luck.
Xyko

Re: rlogin to linux box slow

jane zhang — Thu, 02 Jun 2005 13:00:12 GMT

Hello,

It turns out the box has an older version of bios and cpu clock speed is set to 2.8GHZ for its 3.6GHZ processor.

I update the bios and cpu clock automatically set to 3.6GHZ. the machine is now as quick as others.

Thank you all for the hints, particularly Stuart.

Jane

Re: rlogin to linux box slow

Tvs — Thu, 18 Aug 2005 06:37:19 GMT

hai

just reconfigure the network .