Re: how to make more than 256 pty/tty ?

David Fries (dfries@mail.win.org)
Sat, 30 May 1998 23:21:04 -0500


On Sat, May 30, 1998 at 06:50:01AM +0800, Yin Dadian wrote:
> Hi: all
> I have a slackware 3.4 kernel 2.0.30 128M memory .I need it to support
> 512 users online. After i asked questions "how many users slackware
> support?", Mr.Perry Harrington told me that i must change file
> "/usr/src/linux/include/linux/task.h". I changed the file as he said. And
> rebuild my linux kernel. And reboot.
> Now, the error "fork try again" do not display when someone try to
> login. But new problem come: when someone try to login , system will display
> "All network ports in use" if system have 250 users or almost.
> As you know, when a user login, he will use one pty?? and one tty??. But
> slackware only have 256 pty/tty default.
> So, who can tell me how to make other 256 pty/tty? I have a telnetd , it
> support 512 users already.
> I am exigent with this.
> Thanks a lot.

--------------from kernel help-----------------------
/dev/pts filesystem (experimental)
CONFIG_DEVPTS_FS
If you say Y here, you'll get a virtual filesystem which can be
mounted on /dev/pts with "mount -t devpts". This, together with the
pseudo terminal master multiplexer /dev/ptmx is used for pseudo
terminal support as described in the Open Group's Unix98 standard:
in order to acquire a pseudo terminal, a process opens /dev/ptmx;
the number of the pseudo terminal is then made available to the
process and the pseudo terminal slave can be accessed as
/dev/pts/<number>. What was traditionally /dev/ttyp2 will then be
/dev/pts/2, for example. The GNU C library glibc 2.1 contains the
requisite support for this mode of operation.

This code is also available as a module called devpts.o ( = code
which can be inserted in and removed from the running kernel
whenever you want). If you want to compile it as a module, say M
here and read Documentation/modules.txt.
-----------------------------------------------------

Wouldn't this let you have more than 256 terminals open? Or is it limited
just like the regular terminals are? Also, is there a place to find more
information on how to use it?

I don't have a need for that many open at once (right now), but obviously
others do.

-- 
		+---------------------------------+
		|      David Fries                |
		|      dfries@mail.win.org        |
		+---------------------------------+

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