Adam Thornton writes:
> On Wed, 2004-06-09 at 20:44, Ranga Nathan wrote:
> > Thanks Adam.... I have given our zipl.conf below. From what you say, we
> > should be OK.
>
> Well, as long as 230A is the *first* DASD that's detected, you should
> be. If something else comes up as /dev/dasda you have problems.
The line in zipl.conf was
parameters="dasd=2300-230F root=/dev/dasda1"
which means that Linux will allocate a "slot" for each abstract device
number from 2300 to 230F regardless of whether each is available,
online or whatever. So /dev/dasda will always refer to device 2300,
/dev/dasdb will always refer to 2301 and device 230A would always be
/dev/dasdk. That means that it is not going to work if the root disk
suddenly becomes 230A.
The best solution, as others have suggested, is probably to arrange
for the device numbers to be the same at both sites. In the absence of
that, you can remove the dependency on device numbers for all non-root
fileystems either by using mount-by-filesystem-label (for ext2/ext3,
using e2label and "LABEL=foo" in /etc/fstab instead of the device name)
or LVM (which pools together all PVs--physical volumes--and sorts out
the logical volumes itself). However, that doesn't help for the root
filesystem which needs explicitly coding in /etc/zipl.conf. In the
absence of a boot-time choice of image and arguments, the only way
would be to create a little initrd (with mkinitd) on which you can put
a little script or program to query where you're running and choose
your own root filesystem early in the boot procedure. I still think it
would be easier all around to get the device numbers to match though
[subliminal message: VM, VM, VM].
--Malcolm
--
Malcolm Beattie <[EMAIL PROTECTED]>
Linux Technical Consultant
IBM EMEA Enterprise Server Group...
...from home, speaking only for myself
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