mbr@aoa.UUCP (Mark Rosenthal) (10/05/89)
We're running Ultrix 3.0 on a VAX 8650. Most people log in via ethernet.
We've recently added some X-servers, and now that users can open several
windows at once, the number of pseudo-ttys in use at any one time has
increased. We recently ran out of pseudo-ttys, so we created more special
files in /dev, and added the appropriate lines to /etc/ttys. I thought it
was probably necessary to allocate more kernel space as well, so I checked
in the Ultrix-32 documentation, System Management Volume 2. The manual is
entitled Ultrix-32 Guide to System Configuration File Maintenance. In section
"1.3.4 Pseudodevice Definitions" on page 1-16, it states:
"Each pseudodevice definition line in the config file defines a driver
for a particular pseudodevice. Each pseudodevice definition line begins
with the keyword pseudodevice, followed by the pseudodevice name. The
format is:
pseudo-device name [max n]
The name is the name of the pseudodevice. Configuration files can have
the following pseudodevice names:
pty For pseudoterminal support (default = 16, specify max n for
more than 16)."
So, thinking no harm, I modified the config file to read:
pseudo-device pty max 64
and ran config, which promptly complained about the syntax of the line
immediately preceding the one I had modified.
It also occurs to me that we have been running fine with 32 pseudo-ttys
(tty[pq][0-f]), and if the documentation is to be believed, we should long
ago have run into a limit when we exceeded 16 pseudo-ttys.
So, what gives? Does the kernel allocate them dynamically as needed?
Am I doing something wrong, or is the documentation just plain wrong?
--
Mark of the Valley of Roses
...!bbn.com!aoa!mbralan@shodha.dec.com ( Alan's Home for Wayward Notes File.) (10/05/89)
In article <952@aoa.UUCP>, mbr@aoa.UUCP (Mark Rosenthal) writes: > > > [ The customer wants more pseudo-terminals... ] > > [ Quotes part of the Guide to System Configuration. ] > > pty For pseudoterminal support (default = 16, specify max n for > more than 16)." > > So, thinking no harm, I modified the config file to read: > > pseudo-device pty max 64 > Leave off the "max" and it should work. pseudo-device pty 64 It sounds like the documentation is being unclear about what you're supposed to do. The part about the default being 16 also seems to be a bit of a mystery to me. Check the file pty.h in your kernel build directory and see how many it says. For the configuration file for my VAX 8800 it said 64, but a test configuration file gave 1. Please use the Reader Comment sheet at the end of the manual to our documentation group know that that section needs to be clarified. > Mark of the Valley of Roses > ...!bbn.com!aoa!mbr -- Alan Rollow alan@nabeth.enet.dec.com
alan@shodha.dec.com ( Alan's Home for Wayward Notes File.) (10/05/89)
In article <439@shodha.dec.com>, alan@shodha.dec.com ( Alan's Home for Wayward Notes File.) writes: > The part about the default being 16 also seems to be a > bit of a mystery to me. If you look in /sys/data/tty_pty_data.c the mystery of the default number of pty's will be solved. For those not wishing to look, the default is 32. -- Alan Rollow alan@nabeth.enet.dec.com
grr@cbmvax.UUCP (George Robbins) (10/05/89)
In article <952@aoa.UUCP> mbr@aoa (Mark Rosenthal) writes: > > "Each pseudodevice definition line in the config file... > pseudo-device pty max 64 ^^^ pseudo-device pty 64 Don't be so literal. 8-) -- George Robbins - now working for, uucp: {uunet|pyramid|rutgers}!cbmvax!grr but no way officially representing arpa: cbmvax!grr@uunet.uu.net Commodore, Engineering Department fone: 215-431-9255 (only by moonlite)
mbr@aoa.UUCP (Mark Rosenthal) (10/06/89)
In article <952@aoa.UUCP>, I asked how to configure a kernel for additional ptys. I mistakenly interpreted (italic)"max n" in the manual as if it were (bold)"max" (italic) "n", which led me to include "max" as a keyword in the pseudo-device line in the config file. Thanks for the responses. I've got it working now. In article <439@shodha.dec.com> alan@shodha.dec.com ( Alan's Home for Wayward Notes File.) writes: > It sounds like the documentation is being unclear about > what you're supposed to do. The part about the default > being 16 also seems to be a bit of a mystery to me. Check > the file pty.h in your kernel build directory and see > how many it says. For the configuration file for my VAX > 8800 it said 64, but a test configuration file gave 1. I can explain this mystery. The file /sys/data/tty_pty_data.c contains the following code: #if NPTY == 1 #undef NPTY #define NPTY 32 /* crude XXX */ #endif The documentation clearly should say that the default is 32, not 16. Thanks to all who responded. -- Mark of the Valley of Roses ...!bbn.com!aoa!mbr