Hello,

using our local mirror, i've faced a problem in yum upgrade.
It's look like, there are outdated repodata/primary.xml.gz
in 47/*/errata/SL/RPMS/ subtrees.

yum clean all
yum upgrade

complain about
ftp://l4u.jinr.ru/pub/SL/4x/x86_64/errata/SL/RPMS/repodata/primary.xml.gz: 
[Errno -1] Metadata file does not match checksum
Trying other mirror.
primary.xml.gz            100% |=========================| 2.7 kB    00:00
ftp://ftp.scientificlinux.org/linux/scientific/4x/x86_64/errata/SL/RPMS/repodata/primary.xml.gz: 
[Errno -1] Metadata file does not match checksum
Trying other mirror.
Error: failure: repodata/primary.xml.gz from sl-errata: [Errno 256] No 
more mirrors to try.

I've tried to recreate repodata locally and this is solved the problem
in our own local mirror.

-- 
Best regards,
  Valery Mitsyn