Some handy things to know about when installing Red Hat Linux

Hints in general, and for 4.2 specifically (5.0 hints down lower!)

• Good references for Linux are at www.linux.org and at www.redhat.com ; for Laptop Linux try the Linux on a Laptop page at Linux.org, and the Linux Laptop page at UTexas

• Go ahead and "install everything" - it's easier to do that than to pick and choose. It's also much easier to get rid of stuff you don't need later rather than figure out what you want to add.

• If you "installed everything", your HOWTOs are already on disk at /usr/doc/HOWTO . You may have to cd there and

  	gunzip *
  

  to uncompress them before you can read them (Grail, at least, wants to see them uncompressed.

• to update the 'locate' database, su root and type "updatedb" Then you can use 'locate ' instead of find; locate is MUCH faster.

• If you want source (and didn't install it already) just load the CDROM into the drive, and

  	mount -t iso9660 /dev/cdrom /mnt/cdrom
  

  and launch the package manager tool. Or RPM it in manually; the package you want is kernel-source-whicheverversionyouhave.

• when rebuilding the kernel, you should
  • copy *everything* you want to preserve to another system first. Or at least another disk, preferably removable media.
  • cd /boot
  • copy your current bootable kernel (typically named /boot/vmlinuz) to another file, so you have a fallback position.
  • cd /etc
  • edit lilo.conf, to rename your current bootable kernel to something other than vmlinuz-nn.nn.nn
  • add an entry to lilo.conf to point to what your current (soon-to-be-overwritten) kernel is named. That will be your "new test kernel"
  • run /sbin/lilo to write the new configuration to the MBR.
  • [optional - cd /lib/modules; mv will effectively hide all the old modules which may or may not work ]
  • cd /usr/src/linux
  • [optional - make mrproper will clean up *everything*]
  • make menuconfig or make xconfig (if you have X running already- nicer interface)
  • make dep
  • make clean
  • make install /* this takes a while */
  • make modules
  • make modules_install
  then you can give the new kernel a whirl.

• You probably want to set your domain masquerade (i.e. the domain you want to have appear in your outgoing mail). Do this by editing the file /etc/sendmail.cf; find the line that looks exactly like the one below (starting in column 1)

  	DM
  

  and change it to

  	DMyour.domain.here
  

• Xwindows is configured by the file

  		/usr/X11R6/lib/X11/XF86Config
  

• FVWM (and FVWM95) are configured not by what you are led to believe by the docs, but by files in

  		/etc/X11/TheNextLevel/
  

  This directory looks empty, but it is actually *FULL* of hidden (i.e. first-character-is-a-dot) files; do an ls -a to see them. The one you probably want to play with first of all is .fvwm2rc.defines .

• to get yp running, edit /etc/yp.conf, add the lines:

  	domain your_domain
  	ypserver your_ypserver
  

  and edit /etc/rc.d/rc.local; add the line

  	domainname your_domain
  

  somewhere near the end.

• When you mount your remote filesystems, many NFS fileservers are much happier if you use the options 'rsize=8192,wsize=8192' (which increases the read and write blocksize to something efficiently handled).

• When you mount your remote filesystems, _you_ will be much happier if you use the options 'soft, intr', to make the mounts soft and interruptible. That way you won't hang if the network gets an upset tummy. (this tip and the rsize/wsize tip are compatible).

• make _sure_ your /tmp directory is on your local disk, not NFS mounted to somewhere else!

• When troubleshooting kernel problems, remove the list of supported devices down to those you *need*.

• Loadable kernel modules are sneaky. Check /etc/conf.modules to see if the system is trying to use an already established device as a module.

• Options you may want to put into your kernel build (or rebuild)
  • Pentium Pro CPU - tested and found to be OK (kinda nice, actually)
  • turning on sound (plus /dev/audio and /dev/dsp) - tested and found OK.

• If you can, make your machine dual-bootable with LILO.

• The Gimp as of version 0.99.22 installs without a hitch on 4.2 . You will also need the appropriate gtk+ kit from the same page; gtk+ also installs without a hitch but be sure to edit your /etc/ld.so.conf file to include wherever it is you installed gtk+, and run ldconfig to make the library known.

• If you build your kernel with modular SCSI, and then build the pcmcia services, you do _not_ get an autoload of the SCSI modules, even when booting. Thus, a Bus Toaster or similar SCSI PCMCIA card will not get loaded up correctly. The fix, fortunately, is simple.
  • build your kernel with modular SCSI
  • boot as you usually do
  • to wake up your bus toaster or other PCMCIA SCSI:

         insert the PCMCIA card (hot plugging is OK!)
         type "insmod scsi_mod" to load in the modular SCSI driver
         type "/etc/rc.d/rc3.d/S45Spcmcia restart"  (*)
    

  and your SCSI PCMCIA will wake up running.

  (*) This is where rc.d put my pcmcia startup script. Yours may be different, especially if you've mucked with the startup order. You may have to grep around to find out precisely where it is. [thanks, Jim P.!]

  Note- this hint is superceded by the new card services (2.9.12 and later) which are very smart and in general work correctly even with hotplugging.

• When you first install Linux, you may find that it takes forever (well, several minutes) for Emacs to start, or for an X window manager to start. The problem is that you've forgotten to tell the machine what it's name is in the right way. So, it's going out to find a nameserver and only starting Emacs or X once the network request times out.

  The fix is to go into /etc/hosts and add a line that says your nominal machine name (including domain, like foo.bar.com ) and the four-octet IP address (like 123.123.234.88 or whatever). This will make Emacs and X start much more quickly, because they won't go off looking for a nameserver just to start an edit session.

• If you have more than 64 megabytes (lucky scum) you need to tell Linux to use it. You do this by adding an "append" statement into the file /etc/lilo.conf, like this (if you happened to have 144Megs):

          image=/boot/vmlinuz-2.0.34-0.6
              append="mem=144M"
              label=linux
              root=/dev/hda2
  

  (this hint couirtesy of John T. at Network Consulting / Mindspring)

Hints for 5.0 that are different than 4.2 <-- NEW!! 7-April-1998

• The FVWM95 files have moved yet again. Now, FVWM95 is configured by the files in

       /etc/X11/AnotherLevel/
  

  The file you probably want to tweak first is

       /etc/X11/AnotherLevel/fvwm2rc.defines
  

• Likewise, the XF86Config file is now easily reached via the link at:

       /etc/X11/XF86Config
  

  which is where you configure things like your video card, etc.

• Bummer department: TkDesk as of 6-April-1998 does not run under 5.0 because TkDesk wants a pre-version-8 version of Tcl/Tk. No workaround found for this yet, but I bet a hack of the install script would be all that's necessary (i.e. accept any version of Tcl/Tk at least 7.mumble onward...)

• The Gimp as of version 0.99.22 installs on RH5.0 but you will have to manually define the symbol LD_RUN_PATH to contain the directory of wherever you installed the gtk+ library. For some bizarre reason, you do NOT need to do this under Red Hat 4.2 . You will also need the appropriate gtk+ kit from the same page; gtk+ also installs without a hitch but be sure to edit your /etc/ld.so.conf file to include wherever it is you installed gtk+, and then run ldconfig to make the library known.