Downgrading Glibc Versions

[Ian Burrell]

Browder, Tom <Tom.Browder <at> fwb.srs.com> writes:
> 
> I recently used yum to upgrade my glibc which went to version 2.4.
> Unfortunately I need to maintain another system runnning FC 4 with no
> glibc later than 2.3.
> 
> I am reluctant to tinker with glibc other than through credible rpms
> because of its criticality for the whole system.
> 
> Is there any way to downgrade my FC 5 back to glibc 2.3 or upgrade my FC
> 4 to glibc 2.4 without a manual compilation of glibc or updating the FC
> 4 to FC 5?
> 

What are you trying to do?  FC4 is using glibc 2.3 and FC5 uses glibc 2.4.  If
you want FC4 with glibc 2.3, just leave it alone.  You may be able to run FC4
with FC5's glibc 2.4.  But you will build packages that require glibc 2.4 and
won't install on the FC4 machine.  You won't be able to downgrade FC5 to glibc
2.3.  Every package requires "libc.so.6(GLIBC_2.4)".

If you need to build packages or software for FC4 while running FC5, you can use
a chroot or virtualization.  mock makes clean chroot's for building RPMs.  You
can do something similar for building software manually.  For a while, I ran the
FC5 rawhide as my primary distribution and chroot'ed to my old FC4 installation
for running applications and doing FC4 development.  Or you could use VMware or
Xen for full virtualization.

 - Ian