Unix Training - Unix Tutorials

[2003-03-31] User Friendly Date Script
Setdate The "setdate" is just a more user-friendly front end to changing the date and time:

[2003-03-28] Why is my system so slow?
This is not a performance tuning article. If your system is always slow, this article may not be what you are looking for. I'll be covering some general performance related issues here, but the main focus is for the system that was running fine yesterday but is sucking mud today. The typical response to such problems is "Reboot it", and while that may indeed fix the problem, it does not address the root cause, so you are likely to have the situation again.

[2003-03-27] Sendmail
Sendmail can be a little scary. If the 1,000+ page O'Reilly reference doesn't give you pause, the cryptic configuration files probably will. But actually, if you can put up with a little pain to get by the basics, Sendmail really isn't all that difficult. It is complicated, but a few "rules of the road" will allow you to understand it.

[2003-03-27] Library Cross Reference
This is a cross reference of libraries needed by Skunkware and other binary packages and where to obtain the library or other needed tool. You know you need a library when the program fails to work; sometimes it is friendly enough to tell you what it needs, but sometimes it is not.

[2003-03-27] Using sudo
Most Unix systems have some way of letting ordinary users perform certain tasks as root or some other privileged user. SCO Open Server has "asroot" and can also directly assign "authorizations" such as backup privileges or being able to change other user's passwords. SCO Unixware/Open Unix 8 have a similar facility in "tfadmin". Many Unixes, and Linux, use "sudo". The configuration of sudo is by the /etc/sudoers file. I'm sure that there are more poorly written man pages, but "man sudoers" is among my all time favorites for obfuscation and poor explanation. The creation of the file and the actual use of sudo isn't all that bad though.

[2003-03-26] Tape Drive or CDROM Not Found
Creating a tape drive or cdrom should be simple: run "mkdev tape" or "mkdev cdrom" and answer the questions, relink a new kernel, reboot and it is done. Unfortunately, people seem to have a lot of problems with this. (For the remainder of this article I'll be referring only to tape drives. Everything said applies equally to cdroms or indeed any scsi or ide device being added).

[2003-03-26] SME Server (E-Smith) Mail Forwarding, Lists, Etc.
The Mitel Networks SME Server (formerly E-Smith)is a friendly web server and e-mail gateway. The original E-Smith is now called Mitel SME Server V5. There is also a hardware/software bundle referred to as the Mitel 6000 Managed Application Server. Here we cover forwarding email to another mail account and mailing lists.

[2003-03-26] Noted in Passing June 2002
These are things I'm too busy too look into in depth, but caught my interest somewhere recently, and might be of interest to you also.

[2003-03-26] SME Server V5 Virtual Domains
The Mitel Networks SME Server (formerly E-Smith) is a friendly web server and e-mail gateway. Here we cover creating a virtual domain and giving a user or users ftp access to it.

[2003-03-25] Notify Cell Phone of Incoming Mail
Read this Disclaimer Many cell phones now have the ability to receive email. While that can be very useful, large messages are often a problem both because they are hard to read and because one large message may be split up into multiple messages at the phone. Sometimes, though, it's important that certain messages get to you even though they may be large. That's the situation one of my Mitel (E-Smith) mail server customers had: mail sent to a certain account was very important to know about, but he didn't want the entire message shipped to his cell phone. As it turns out, this was an easy problem to solve.

[2003-03-25] SCO Openserver release 5.0.7
Disclaimer There is a lot to like in the 5.0.7 release of SCO Openserver. Support for IDE CD-RW and DVD-RAM (you need other tools to actually write to this media, but the important kernel support is built in), more USB devices (though not printers or modems), P4, Xeon, and AMD Athlon processors, UDMA 100 and 133 hard drives, PCI serial and parallel cards, LS-120 and LS-240 IDE drives (see "man Sflp", not "sflp" as the documentation suggests) , several Gigabit network cards, and more PCMCIA support. The Netscape server is gone, replaced by Apache, OpenSSH is built in, sendmail is at 8.11 (which of course will need immediate updating), and you now have a choice of Mozilla or Netscape for GUI browsers and Lynx is included for character mode.

[2003-03-25] Too many messages for Outlook Express
Read the Disclaimer Recently one of my Mitel SME Server clients took two weeks off. When he returned, Outlook Express told him he had 23,000 messages waiting on the server! Unfortunately, Outlook Express couldn't bring any of those messages to his PC; it just hung.

[2003-03-25] 3.2v4.2 System Recovery
Disclaimer I was called in recently to help with the recovery of an old SCO 3.2v4.2 system that had crashed. The crash had initially been caused by a power supply failure, but after replacing that hardware, the machine would not boot - it just hung after the kernel i/o buffers message. As a common cause for that is simply a missing or damaged inittab, I thought we might be able to fix it by booting from floppies and doing a manual repair. Unfortunately, there were no emergency boot floppies.