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Problems with logins ( seem to hit a wall at 60 rlogin sessions)

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rmueller58
Valued Contributor

Problems with logins ( seem to hit a wall at 60 rlogin sessions)

Hi,

We have a newly installed HP/UX 11.0 system where we have problems with a client package that uses "rlogin" when we reach approximately sixty users #61 dies on us.

If we log in a root we can get past this limit and for a period it seems to work, but our vendor has been scratching there heads trying to figure it out.. They made changes to kernel parameters and we wait for reboot only to find out the next day that we are still in the same boat. (This has been going for a month.)
This action is not acceptable to my management they want a solution now..
I thought I'd take it to the source.






39 REPLIES
John Waller
Esteemed Contributor
Solution

Re: Problems with logins ( seem to hit a wall at 60 rlogin sessions)

Do you know if npty and nstrpty have been increased in the kernel. On my system both these are set to 60 and these do control the psudo tty devices used when you rlogin into a system
rmueller58
Valued Contributor

Re: Problems with logins ( seem to hit a wall at 60 rlogin sessions)

John,

Yes we have changed both kernel parameters..

Rex
Bill McNAMARA_1
Honored Contributor

Re: Problems with logins ( seem to hit a wall at 60 rlogin sessions)

Here a link to a solution of a similar problem:

http://forums.itrc.hp.com/cm/QuestionAnswer/1,1150,0xf984663ce855d511abcd0090277a778c,00.html

Later,
Bill
It works for me (tm)
Jim Turner
Esteemed Contributor

Re: Problems with logins ( seem to hit a wall at 60 rlogin sessions)

You didn't specify which kernel parms your vendor told you to change, but here are the ones that you need to look at:
npty
nstrpty
nstrtel

All three are set to 60 out of the box. Set them to about 20% more than the maximum number of users you're expecting. Give the resulting kernel a try, and I think you'll find your problem is solved.

Cheers,
Jim
Bill McNAMARA_1
Honored Contributor

Re: Problems with logins ( seem to hit a wall at 60 rlogin sessions)

http://forums.itrc.hp.com/cm/QuestionAnswer/1,1150,0x9ca00cb17a32d5118fef0090279cd0f9,00.html

Seems that either way you'll be limited.. but to 512.

Later,
Bill
It works for me (tm)
rmueller58
Valued Contributor

Re: Problems with logins ( seem to hit a wall at 60 rlogin sessions)

Mr Turner,

we changed NSTRPTY, NPTY, maxuprc, maxusers, nstrtel,

to name a few...

Rex
Laurent Paumier
Trusted Contributor

Re: Problems with logins ( seem to hit a wall at 60 rlogin sessions)

Did you use sam to increase kernel parameters ? If not, you must create pty device files using insf.
Patrick Wallek
Honored Contributor

Re: Problems with logins ( seem to hit a wall at 60 rlogin sessions)

After you changed the kernel parameters did you rebuild the device files so that you have more available to use for logins. Try doing an 'insf -e' and see if this helps you.
Bill McNAMARA_1
Honored Contributor

Re: Problems with logins ( seem to hit a wall at 60 rlogin sessions)

do you see the device files in /dev/ ?

Later,
Bill
It works for me (tm)
rmueller58
Valued Contributor

Re: Problems with logins ( seem to hit a wall at 60 rlogin sessions)

Is there a way to determine what the current value is ?

Is the INSF -e something i can run while system is up in multiuser?

rmueller58
Valued Contributor

Re: Problems with logins ( seem to hit a wall at 60 rlogin sessions)

Bill M,

I do have
pts, ptym, pty directories


Patrick Wallek
Honored Contributor

Re: Problems with logins ( seem to hit a wall at 60 rlogin sessions)

Yes you can run 'insf -e' while the system is up. Any device files that are currently there will be left alone, the '-e' will only create those that are missing.

If you want to see how many you have look in /dev/ and look for pty, tty and pts files.
Jim Turner
Esteemed Contributor

Re: Problems with logins ( seem to hit a wall at 60 rlogin sessions)

Have a look at KB Doc ID A4317489. Specifically:
This can be caused by not having an entry for those ports in these files:

/tcb/files/devassign
/tcb/files/ttys

A workaround is to add the necessary entries using the following (obscurely
documented) commands:

1. Add an entry to /tcb/files/devassign with a:

/usr/lbin/modprdev -A /dev/device_name

2. Add an entry to /tcb/files/ttys with a:

/usr/lbin/modprterm -A /dev/device_name

For more information on devassign and ttys, refer to your HP-UX Reference
and their respective man pages.

Your additional device files may be there, but if you are running a trusted system, they'll do you no good until you update /tcb/files/devassign and /tcb/files/ttys. As I recall, it was a SAM bug that would create the new devs but not update the tcb files.

And yes, you can do an "insf -e" with the system up and running.

Cheers,
Jim
rmueller58
Valued Contributor

Re: Problems with logins ( seem to hit a wall at 60 rlogin sessions)

Patrick
# pwd
/dev/pts
# ls |wc -l
120
# pwd
/dev/pty
# ls |wc -l
60
/dev/ptym
# ls |wc -l
61
#
The following was information the "vendor"
gave me..

But since we've already established these parameters in a kernel will it be necessary to run this????


To increase pty device files:

Run the following commands in single-user mode.

# insf -d ptys -n 512

# insf -d ptym -n 512

# insf -d pts -s 512 -v

The first two devices ptym and ptys are the master and slave devices
for pty.



Jim Turner
Esteemed Contributor

Re: Problems with logins ( seem to hit a wall at 60 rlogin sessions)

Yes, you do have to create the additional device files, and also update the tcb files as I directed earlier. If you don't do *both* things, you'll still be pooched.

Cheers,
Jim
Patrick Wallek
Honored Contributor

Re: Problems with logins ( seem to hit a wall at 60 rlogin sessions)

Even thoough you've got the appropriate values in the kernel you still need to make sure you've got enough device files. Your pts directory shows that it has 120 lines. That should get you 120 rlogins (or dtterms) if nstrpty is set appropriately. If the kernel parameter nstrpty is set above 120, then go ahead and do the insf for the pts directory so that you have all the appropriate device files.
Patrick Wallek
Honored Contributor

Re: Problems with logins ( seem to hit a wall at 60 rlogin sessions)

You will only be able to modify the /tcb/files area if the system is in trusted mode. If the system is not trusted the /tcb directory structure does not exist.
rmueller58
Valued Contributor

Re: Problems with logins ( seem to hit a wall at 60 rlogin sessions)

Guys,

here was the last kernel tune we did.. 6/4/2001

STRMSGSZ 65535
max_thread_proc 256
maxswapchunks 1604
maxusers 512
ncallout 2064
nfile 51548
nkthread 2048
nstrpty 512
npty 512
nstrtel 512
semmni 4096
semmns 4096
shmmax 2048000000
shmmni 512
shmseg 256
maxtsiz 262144000
maxdsiz 262144000
maxfiles 1024
maxuprc 512
nflocks 2048
nproc 3072
rmueller58
Valued Contributor

Re: Problems with logins ( seem to hit a wall at 60 rlogin sessions)

Pat,

We do use tcb..

Rex
Patrick Wallek
Honored Contributor

Re: Problems with logins ( seem to hit a wall at 60 rlogin sessions)

Do your insf's. I think you'll find that this will help. Here's a document from the TKB you might be interested in as well.

http://us-support.external.hp.com/cki/bin/doc.pl/sid=0f4654081c11768063/screen=ckiDisplayDocument?docId=200000044658519
rmueller58
Valued Contributor

Re: Problems with logins ( seem to hit a wall at 60 rlogin sessions)

Thanks for the assist. You guys are job savers!

Patrick Wallek
Honored Contributor

Re: Problems with logins ( seem to hit a wall at 60 rlogin sessions)

So you can now get more that 60 rlogin sessions?

(When you get a chance, assign points to those that helped)
CHRIS ANORUO
Honored Contributor

Re: Problems with logins ( seem to hit a wall at 60 rlogin sessions)

Ensure that the folowing parameters are increased: Npty, Nstrpty, Nstrtel and Maxusers. And then assign points.
When We Seek To Discover The Best In Others, We Somehow Bring Out The Best In Ourselves.
rmueller58
Valued Contributor

Re: Problems with logins ( seem to hit a wall at 60 rlogin sessions)

Pat,

I ran insf -e, I will monitor to see if the kernel parameters did what we needed.

I haven't looked at the tcb issues yet, but I am sure they "the vendor" overlooked this.

Rex