[PlanetCCRMA] Install of Planet CCRMA for 64-bit Fedora 10 Went Well Except On Rebooting There Is No New rt Kernel

[Fernando Lopez-Lezcano]

On Wed, 2009-03-11 at 15:45 +0900, Sean Beeson wrote:
>                 Hmmm...
>                 What do you see in a terminal if you do:
>                  rpm -q kernel-rt
>                 
>                 If planetccrma-core installed then you should have at
>                 least one realtime
>                 kernel listed there. Then I would check the contents
>                 of /boot/grub/grub.conf, you should have an entry
>                 there for the rt
>                 kernel and it should probably be the default - "index"
>                 points to the 0
>                 based index of the default kernel.
>                 
>                 -- Fernando
>         
>         
>         [root at ceres sean]# rpm -q kernel-rt
>         kernel-rt-2.6.26.8-1.rt16.1.fc10.ccrma.x86_64
>         
>         [root at ceres sean]# cat /boot/grub/grub.conf
>         # grub.conf generated by anaconda
>         #
>         # Note that you do not have to rerun grub after making changes
>         to this file
>         # NOTICE:  You have a /boot partition.  This means that
>         #          all kernel and initrd paths are relative to /boot/,
>         eg.
>         #          root (hd0,0)
>         #          kernel /vmlinuz-version ro
>         root=/dev/VolGroup00/LogVol00
>         #          initrd /initrd-version.img
>         #boot=/dev/sda
>         default=0
>         timeout=3
>         splashimage=(hd0,0)/grub/splash.xpm.gz
>         hiddenmenu
>         title Fedora (2.6.27.19-170.2.35.fc10.x86_64)
>             root (hd0,0)
>             kernel /vmlinuz-2.6.27.19-170.2.35.fc10.x86_64 ro
>         root=UUID=c14b36c6-4eab-4def-b2ec-a33a006c5164 rhgb quiet
>             initrd /initrd-2.6.27.19-170.2.35.fc10.x86_64.img
>         
>         [root at ceres sean]# 
>         
>         -------------------------
>         
>         Is it just a matter of adding my own entry for the kernel in
>         grub? What information should I use there, if so?
>         
>         Thanks,
>         
>         -Sean
> 
> Well, after reading up on adding kernels to grub, I know that I just
> need to make an entry just like what is there which points to the new
> kernel. However, the only initrd img file on my system is the one you
> see in my grub.conf

Then something went wrong with the kernel-rt install. Did you get an
error message perhaps? The kernel should have been automatically added
and configured. 

You should erase the rt kernel ("rpm -e kernel-rt") and install it again
("yum install kernel-rt"). 

> file: /boot/initrd-2.6.27.19-170.2.35.fc10.x86_64.img which is clearly
> is for the vmlinuz-2.6.27.19-170.2.35.fc10.x86_64 kernel. After
> reading further about initrd images, which are for storing drivers in
> a ramdisk so that the kernel can mount / and kick off init and can be
> avoided if you build your drivers right into the kernel instead of
> into modules, a difference to how the planetccrma-core rpm builds its'
> kernel to how the default fc10 kernel gets build is reveled and some
> questions come to mind. Obviously, the planetccrma-core kernel has
> drivers build into it and I should be fine having another entry for
> the rt-kernel without the initrd entry. I guess putting an entry in
> grub and rebooting is going to tell me real fast if my assumptions are
> correct. The questions I have are:
> 
>      1. Are the modules that were in the original fc10 initrd file get
>         put in the new rt-kernel? I am thinking somehow my system
>         needed them, if the default fc10 install put them there.
>      2. If the rt-kernel has all the modules now, how does adding
>         modules in the future work for other hardware and such?

The kernel install process should have create the initrd image and added
the grub entry. I don't know what could have gone wrong. 

>      1. Is that strange root=UUID=c14b36c6-4eab-4def-b2ec-a33a006c5164
>         still needed and, if not, what do I use?

the UUID is the id of the particular disk you are using. 

>      1. How do I go about changing any module or updating it in the
>         future?
>      2. In addition to the current topic, but something I have always
>         wonderd--as yum updates get applied after using the rt-kernel,
>         are these updates being applied to the rt-kernel and do they
>         retain the low latancy of it?

The kernel-rt package has the low latency patches and is not affected by
subsequent upgrades (unless of course a new kernel is installed and
becomes the default choice when booting, then you would have to select
the rt kernel - if the new kernel is the vanilla Fedora kernel). 

> Thanks and currious,

-- Fernando