Kenneth Porter wrote:
On Wednesday, June 27, 2007 9:02 PM -0700 Akemi Yagi amyagi@gmail.com wrote:
Ahem, I know this is a CentOS mailing list. BUT, as more and more people migrate from FC to CentOS, I thought placing this reminder here was worthwhile. [I am still running *cough* FC5 on my own desktop, so I am also running out of time]
For those of us migrating from ancient versions of Fedora, what gotchas might one expect?
If you are using php, you may need to look at programs to make sure they run on newer versions of PHP and upgrade if required (horde needs to be greater than a certain level to run on php-5, for example)
I'm working on migrating from a pre-SELinux Fedora, and SELinux has been the biggest headache so far. I'm also expecting to migrate Dovecot from 0.99 to 1.0, and there's a page on the Dovecot wiki about that. I've seen the recent list traffic about BIND's lack of default config, so I'm expecting that, and it's not a problem.
WRT SELinux ... these are your friends:
chcon -R system_u:object_r:httpd_sys_script_exec_t <path> (lets apache run cgi scripts in directories not in /var/www/cgi-bin)
chcon -R -t httpd_sys_content_t <path> (lets apache access directories outside /var/www/)
many more SELINUX things from here:
man httpd_selinux
and here:
http://www.centos.org/docs/5/html/Deployment_Guide-en-US/selg-overview.html
If you are dealing with apache and a modified httpd.conf file ... the first thing I recommend is that you use /etc/httpd/conf.d/ and a conf file for as many things as possible. Also, to use a different conf file for each kind of service/site within conf.d/
This keeps your httpd.conf file as close to standard as possible, and allows you to easily upgrade to new versions where module names are different, etc. It also allows you to move services/sites over and troubleshoot issues much more easily than a full migration of everything.
One thing I like to do is keep a non modified copy of httpd.conf from the original RPM ... and run a "diff" between the standard and my httpd.conf ... I then know what was changed on that machine ... and can either roll it into the new httpd on the new machine, or split it out to a conf.d/<file>.conf file.
If you did not save the httpd.conf file from your current httpd-<version>.rpm ... you can get it using cpio2rpm like this:
1. get a copy of the original RPM (should be available on a Fedora, RedHat, CentOS, SciLinux, WBWL etc. mirror site that you installed it from)
2. Create a directory and put the RPM in there.
3. CD to the new directory an make sure the only file in there is the RPM.
4. Use this command to extract all the files from that RPM to the current directory:
rpm2cpio <rpm_name> | cpio -idv
5. All the files are now in the current directory in the path that they would have been installed ... so this is the original config file:
<current_directory>/etc/httpd/conf/httpd.conf
My plan is to install CentOS to a new box, and migrate services one by one as needed.
That is the way I recommend doing it. Keep the old one working while you fix the issues on the new one.
Thanks, Johnny Hughes