[PlanetCCRMA] PlanetCCRMA and RAID: which way to go?

Wed Jun 22 16:44:01 2005

On Wed, 2005-06-22 at 11:12 -0700, Fernando Lopez-Lezcano wrote:
> On Wed, 2005-06-22 at 04:32, Henk Jansen wrote:
> > On Wed, 2005-06-22 at 11:45, Steve Harris wrote:
> > > Digging around in the recesses of my memory, that might be because you
> > > need an initrd (a thing that can load certain drivers that are needed
> > > before kenel boot finises. Look on the web for instruction about how to
> > > build one, you will nee the raid and md drivers in your initrd if there
> > > not already.
> > 
> > The planetccrma distribution comes with precompiled initrd-*'s and
> > vmlinuz-*. 
> 
> Hmmm, you should not need to "recompile" them. The initrd image used
> during boot is built at kernel install time using the information about
> peripherials that is part of /etc/modprobe.conf. 

Using the default Fedora Core 3 kernel (2.6.11-1.14_FC3), the raid0
module is loaded and everything is working fine. Yet there's no
mentioning of "raid" of any sorts in the /etc/modprobe.conf file.

The planetccrma software was installed from cdrom using the "apt-get
install ..." procedure --- I asume this is the correct procedure
(including the build of a proper kernel)...

> So, it could be that at
> the time of the install the disk controller was not online and then its
> driver did not get added to the initrd image. You could rebuild the
> image by using mkinitrd ("man mkinitrd" for details). 

This may be it (...or not...): reading the man page for mkinitrd it says
that
<quote>mkinitrd automatically loads filesystem modules (such as ext3 and
jbd), IDE  modules, all scsi_hostadapter entries in /etc/modprob.conf,
and raid modules if the system’s root partition is on raid,
which</quote>...

My system's root partition is on a normal harddrive device *not* on a
raid device (only my /home directory is on a raid device). May therefore
the planetccrma installation procedure have missed to include raid
support... (the raid0 module however lives in the /lib/modules for the
various planetccrma kernels).

> 
> What is the raid device hanging from? 

I don't understand what you mean. Please, can you explain a bit more?

> Are the disks themselves and their
> controller recognized during the boot process? I take it that raid is
> recognized by the original Fedora kernel, right?

Indeed. These are the messages during a boot process with the original
Fedora kernel:

Jun 22 00:51:35 jaki smartd[3936]: Device: /dev/hda, found in smartd
database.
Jun 22 00:51:35 jaki kernel: Freeing unused kernel memory: 180k freed
Jun 22 00:51:36 jaki kernel: md: raid0 personality registered as nr 2
Jun 22 00:51:36 jaki smartd[3936]: Device: /dev/hda, is SMART capable.
Adding to "monitor" list.
Jun 22 00:51:36 jaki kernel: md: Autodetecting RAID arrays.
Jun 22 00:51:36 jaki smartd[3936]: Device: /dev/hde, opened
Jun 22 00:51:36 jaki kernel: md: autorun ...
Jun 22 00:51:36 jaki kernel: md: considering hdg1 ...
Jun 22 00:51:36 jaki kernel: md:  adding hdg1 ...
Jun 22 00:51:36 jaki smartd[3936]: Device: /dev/hde, found in smartd
database.
Jun 22 00:51:36 jaki kernel: md:  adding hde1 ...
Jun 22 00:51:36 jaki kernel: md: created md0
Jun 22 00:51:36 jaki kernel: md: bind<hde1>
Jun 22 00:51:36 jaki kernel: md: bind<hdg1>
Jun 22 00:51:36 jaki kernel: md: running: <hdg1><hde1>
Jun 22 00:51:36 jaki kernel: md0: setting max_sectors to 128, segment
boundary to 32767
Jun 22 00:51:36 jaki kernel: raid0: looking at hdg1
Jun 22 00:51:36 jaki kernel: raid0:   comparing hdg1(58615552) with hdg1
(58615552)
Jun 22 00:51:36 jaki kernel: raid0:   END
Jun 22 00:51:36 jaki kernel: raid0:   ==> UNIQUE
Jun 22 00:51:36 jaki kernel: raid0: 1 zones
Jun 22 00:51:36 jaki kernel: raid0: looking at hde1
Jun 22 00:51:36 jaki kernel: raid0:   comparing hde1(58615552) with hdg1
(58615552)
Jun 22 00:51:36 jaki kernel: raid0:   EQUAL
Jun 22 00:51:36 jaki kernel: raid0: FINAL 1 zones
Jun 22 00:51:36 jaki kernel: raid0: done.
Jun 22 00:51:36 jaki kernel: raid0 : md_size is 117231104 blocks.
Jun 22 00:51:36 jaki kernel: raid0 : conf->hash_spacing is 117231104
blocks.
Jun 22 00:51:36 jaki kernel: raid0 : nb_zone is 1.
Jun 22 00:51:36 jaki kernel: raid0 : Allocating 4 bytes for hash.
Jun 22 00:51:36 jaki kernel: md: ... autorun DONE.
Jun 22 00:51:36 jaki kernel: kjournald starting.  Commit interval 5
seconds

Then partitions hde1 and hdg1 are clearly recognized as raid devices.
What I obtain when trying to boot with the planetccrma kernel is written
below in my first posting.

--Henk

> 
> -- Fernando
> 
> > Are the source codes of the planetccrma kernels available so
> > that I can compile them myself?
> > 
> > Although I'm prepared to compile them myself, I still wonder though
> > whether it's necessary: I get the impression from postings in the
> > mailing list that software RAID is not a problem for the planetccrma
> > kernel... (anyway, it's not a problem for my default Fedora Core 3
> > kernel...).
> > 
> > --Henk
> > 
> > (Sorry Steve for the duplicate mailing.)
> > 
> > > 
> > > - Steve
> > > 
> > > On Wed, Jun 22, 2005 at 02:48:18 +0200, Henk Jansen wrote:
> > > > I've succesfully installed the PlanetCCRMA software for my Fedora 3
> > > > system. However, using the low latency kernel
> > > > (...-2.6.10-2.1.ll.rhfc3.ccrma.img) the booting process halted when it
> > > > had to startup my raid device (/dev/md0) with message:
> > > > 
> > > > """
> > > > Checking filesystems
> > > > fsck.ext3: Invalid argument while trying to open /dev/md0 [FAILED]
> > > > """
> > > > 
> > > > (...me ending up in rescue mode). How should I proceed in trying to get
> > > > the kernel working with my raid configuration? Anyone dealt with this
> > > > problem before? Thanks.
> 
> 
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