Gentoo Linux Hints and Tips

I have worked with Gentoo Linux now for a few years, see: http://www.gentoo.org/doc/en/handbook/index.xml

Whilst I am not exactly a "newbie" I don't do this often enough to remember all the tricks. Therefore I will post some information here in case it helps others to get their systems running as they want them. I have always used UNIX, from the mid 1980s. I have worked with SunOS, Solaris, AIX, Linux, and many other flavours. Since my fiends and I built own first PCs in the mid 1970s and moved onto scientific supercomputing at work, this is perhaps understandable.

Several people in my software development group started using Gentoo Linux. It is less known than the "popular" distros, but also very popular. Its great strength is that everything, yes everything, is configurable. You can have all or nothing!

Many of the issues addressed here are related to installation problems. In this respect each distro is different, but stick wich the one you prefer. Linux is evolving rapidly and what is a problem today may not appear in these pages in future. Typically, if you find something doesn't work first time and there are lots of blogs about it, then it must be new and not yet fully supported. Be patient, either work around it like I have, or wait for a stable solution from your distro supplier.

Gentoo is no different from other Linux distros in this respect. It is in my opinion fun to use and a fantastic learning experience. A working Gentoo distribution also appears to be totally stable in my experience on both desktop and laptop systems.

The current set of Gentoo documentation is here: http://www.gentoo.org/doc/en/list.xml

Some more Linux things here: http://www.ibm.com/developerworks/linux/library/l-10sysadtips/?cmp=dw&cpb=dwlin&ct=dwnew&cr=dwnen&ccy=zz&csr=010512

Setting the data and time

I keep forgetting how to do this, so here are some notes. To set the system time and date do:

date -s "yyyy-mm-dd hh:mm:ss"

To sync the hardware clock to this system time do

hwclock --systohc

It is also advisable to run ntpd. Note that ntp-client is now deprecated. See http://en.gentoo-wiki.com/wiki/NTP

Grub

The last few Gentoo 2008.0 installs I did had an odd problem. The Grub menu does not show and the screen goes "crinkly". This is fixed by hashing out the splashimage line in the grub.conf file.

Older systems might have /boot as an ext2 file system. Don't forget to enable ext2 support if updating the kernel or you would not be able to save the boot image and edit grub.conf.

Hardware Testing

• to test the memory, get a memtest disk and boot it.
• use fsck to test the disk systems
• use smartmontools to check for disk problems
• try lm_sensors to monitor system parameters, including temperature

Maintaining File Systems

See IBM Linux 101

Problems with Devices

I had a problem with 2.6.31 where k3b could not find an optical disk writer. Eventually after trawling the Web I solved this problem as follows:

1. add user to cdrom, cdrw and hotplug groups
2. add apci to USE flags in /etc/make.conf
3. emerge and update hald
4. emerge and update dbus; /etc/init.d/dbus restart - this also restarts hald
5. emerge and update k3b

Systems

Current installations I have are:

• Acer Ferrari 3400 laptop
• Acer T180 desktop
• Acer Ferrari 4000 laptop
• Viglen dual-core desktop
• Viglen Genie Pro Xeon desktop
• IBM eServer x-Series 335
• Time Computer

Click on the above links for information about these installations.

Special Topics

• Ten Hints for Linux Admins
• LD_LIBRARY_PATH and LD_RUN_PATH
• FGLRX Troubles
• Projecting Video
• Vista Dual Boot
• Green Computing
• Wirless Works
• HPC with Gentoo
• Open Source Software
• ipTables
• using Tripwire