UNIX Sysadmin Resources – FAQs Sun Microsysems
When a Sun receives a BREAK signal on the console serial port, it normally drops to the prom monitor prompt, just as if you had pressed the Sun
keyboard’s <STOP><A>. If you have a terminal plugged into the console serial port, you will often get the BREAK when you remove the
terminal’s serial cable or power off the terminal. But, that’s not what you usually want to happen. (You can’t send a BREAK via the normal
Hyperterminal on Windows NT4. We suggest using the free Tera Term and an SSH extension, TTSSH.) You can change the Sun’s serial port BREAK behavior, and we’ll tell you how. But first…..
What’s a BREAK? (This excellent description was lifted from Greg ndrews)
The BREAK signal is where the terminal (or terminal server) sets its transmit data line to a steady positive voltage for a period of time. Normally, the transmit line is not at a steady positive voltage. The stop bit in each character transmitted would interrupt any positive voltage and send it negative. In order to be accepted as a BREAK signal (and not merely a glitch), the signal would need to be positive for longer than it takes to receive 3 characters. Suns usually listen on their RS232 console ports at 9600 bps, or 960 characters per second (8 data + 1 start + 1 stop = 10 bits per character). That’s roughly one character per millisecond. So, the transmit line would have to be steadily positive for 3-4 milliseconds for the Sun to think it was a BREAK signal. Suns can accept RS423 (+/- 5V) signals as well as RS232 (+/- 12V) signals. The voltage threshold for an RS423 signal is around 3.5 Volts. So, a signal glitch that stays above +3.5 Volts for 4 milliseconds can make the Sun think someone’s sending a BREAK signal. If the terminal or terminal server is not careful to clamp its outputs when the power supplies are charging up (power on) or discharging (power off), such a glitch would be easy to generate. Under certain conditions of cable capacitance and/or inductance, just unplugging the RS232 cable can also produce a glitch on the Sun’s receive pin that looks like a BREAK signal.
Terminal Server BREAK-off: See the results of testing many different terminal servers, and whether or not they send expected or unexpected BREAKs. Test methodology also included. Excellent work.
Power-switch key method:
On Enterprise-type Suns, the power switch has four positions: off, on, diagnostic and secure. With the power switch in the secure position, the system ignores BREAKs generated by keyboard reconnect, serial terminal loss, Stop-a or a serial terminal BREAK key.
Sun has released patches to address the issue of BREAK on console serial ports. These patches are available only to Sun contract customers from
sunsolve.sun.com. According to Sun Infodoc 21258, these patches now work on Netra machines and Solaris 8 does not require this patch. On servers with a physical keyswitch, the alternate BREAK does not work when the key is set to the Secure position. Solaris 2.6 requires patch 105924-10 or higher. Solaris 2.7 requires patch 107589-02 or higher. Unlike previous fixes, it retains the ability to force a hanging system to halt when required, without allowing random or spurious BREAKs to cause an unintentional stop. The new sequence to stop the system is:
[CARRIAGE RETURN] [~] [CONTROL B] (The [ and ] characters are here just for readability. You enter the Carriage Return/Enter key, the tilde key, then control-b.)
There must be more than 0.5 seconds between characters, and the string must be entered in less than 5 seconds.
Solaris 2.6 and higher: In
/etc/default/kbd, add the variable
KEYBOARD_ABORT=disable then use the command
kbd -i which reads
/etc/default/kbd and disables keyboard abort. You can also toggle between enable and disabled using
kbd -a disable and
kbd -a enable. See the
kbd man page for more detail. This method works on the Netra T105, too.
nobreak for Solaris is a set of init scripts and runlevel links to run the commands for you through a pkgadd package. Provided by Martin Schmitt.
External device method:
A model NUD4273 “non-aborting serial console adapter” from NUData will prevent the BREAK signal from ever reaching the console port. The devices cost about $89 USD each. They can be purchaed through Micro Warehouse.
comp.sys.sun.admin FAQ compiled by Rob Montjoy. Mainly covers information for SunOS 4.1.x.
Custom Solaris System Administration Labs are excellent, clear how-tos covering at least Solstice DiskSuite Command Line Configuration, Configuring A NIS+ Master/Home Directory Server and Clients, Configuring Solaris Jumpstart Without a Name Service, and Generic Interactive UNIX Shell Prompts. Provided by Jon C. LeBlanc,
Unix Certified Instructor.
Halvard’s Cookbook for Using DLTs on SunOS 4.1.x and 5.x explains how to set up and use DLT 2000 and 4000 half inch tape drives. Old but highly useful document for configuring a “non supported” drive.
Increasing the number of ptys: The truth about sadcnt, nautopush, pt_cnt and npty is the truth from Casper Dik, trying to stamp out the myth.
Serial Console on a Sun or SGI System is an excellent how-to for serial console connections. Covers ports, wiring, terminal settings. Great pictures.
Solaris Fact Sheet and SunOS Fact Sheet are great quick-references for the release dates, costs, supported hardware, graphics engines, UI, and much more. Part of a comprehensive Operating System Technical Comparison from OSdata.com.
Solaris OS, Networking and Others FAQS contains valuable tip sheets on (at least) Printing, migration, networking, multi IP, TCP/IP, routing, Sendmail, DNS, NFS, automounter, NIS, NIS+, FTP, Disksuite, power management, error messages, OS/architecture matrix. We’re glad these have been posted. From Electronic Business Solutions, Inc.
Solaris 2.x FAQ edited by Casper Dik.
Solaris 2.6 Official FAQs includes lists of new features, whitepapers, and more. See also the Solaris Support site from Sun.
Solaris 7 Product Line FAQs from Sun Microsystems.
Solaris 7 Resources at Kempston is a great collection which covers PPP, configuring mail (SMTP, fetchmail/POP3), installing software, gcc, TCP wrappers, samba, and more. Maintained by Mike Mann.
Solaris Developer Connection has all the latest downloads, code samples, patches, FAQs, technology articles, training information, drivers, compatibility lists, driver development information, boot floppies for Solaris Intel and demos for the Solaris operating environment.
Solaris OE Guide for New System Administrators contains the most relevant 20% of technical information you will need to know when working with Solaris and Sun platforms and should answer 80% of your Solaris questions. Well done from the folks at Sun’s BigAdmin.
Solaris Volume Management using your choice of Solstice DiskSuite or Veritas volume manager. Excellent information on installation and maintenance. Extensive reference guides.
Sun Blade 100/150 FAQ Wiki, Unofficial FAQ covering hardware, software and firmware.
Sun NVRAM/hostid FAQ, by Mark Henderson.
Sun Managers FAQ edited by John DiMarco. Don’t miss the Sun Managers Read Before Posting information.
Master Sun format.dat, maintained by John DiMarco.
Sun Hardware FAQ covers older Sun models, from the Sun-1 through Sun-4. No longer maintained, but still a useful reference from James W. Birdsall.
Sun Colormap FAQ explains how to eliminate colormap flashing and answers lots of other colormap questions. Well-written by David Tong and Sun Microsystems.
Sun FrameBuffer FAQ is loaded with useful info, tools to determine and configure your Sun frame buffer, dual-monitor info, monitor and lots of other video info. Written by David Tong and Sun Microsystems. Also see the
FrameBuffer History Lesson
Sun ONE Architecture Guide provides a technical overview of the components and functionality available from Sun for developing and deploying Services on Demand. The guide breaks the architecture into six easy to understand sections.
Custom Solaris System Administration Labs contains very good how-tos on (at least) Solstice DiskSuite Command Line Configuration, Configuring A NIS+ Master/Home Directory Server and Clients, Configuring Solaris Jumpstart Without a Name Service, and Generic Interactive UNIX Shell Prompts. Written by Jon C. LeBlanc.
The CNS Guide to NIS+ explains how to install, configure, maintain, and troubleshoot Solaris NIS+. PDF and MS word documents. Written by Stuart Kendrick.
FAQABOSS: FAQ About Buying an Old (Used) Sun System gives info about older Suns’ architecture, enclosures, names, equipment. Maintained by Brian Brush.
Graphical monitor/keyboard with serial console: This Sun Infodoc explains how to use a serial console, while having a login also available on the normal Sun monitor and keyboard. Sun’s title for this Infodoc 18318 is “How to run dtlogin on a Solaris [TM] 2.5.1 or higher machine with a ttya console”.
Historical Sun Performance is a comparison table showing Sun models from the SS-1 to U-10000 in MHz, cache, benchmarks, and more. See MobileDyne Public Information for more info on PC fdisk partitions and Unix, Solaris x86 installation, Solaris EIDE drivers and BIOS LBA, mounting PC FAT filesystems on Solaris and more.
LDAP Setup and Configuration (PDF) for Solaris minibook describes how to set up, configure and administer Solaris LDAP client and server systems. Written by Sun Microsystems.
Solaris 8/9 workstation installation (PDF) describes how to install Solaris on a workstation, using DHCP with Cable modem/DSL, and how to add a printer. Written by Howard Welsh.
Solaris Root Shell Mini-FAQ tries to clear up some common misconceptions about changing root’s shell.
Using SPARCPrinter with Ghostscript covers the basics of getting this working on Solaris 2.6. Very useful, since Newsprint isn’t supported on Solaris 2.6.