When upstream released 5.1, everybody wanted to test a new kernel parameter that could adjust the system clock rate at boot time to something else than the standard 1000Hz clock rate. A lot of testings has been done (thanks to Akemi Yagi for her great work) and you can see the results here : http://bugs.centos.org/view.php?id=2189 As you can read at the bottom of the comments, it seems it was a typo in the official RH Release Notes : you'd have to read divider= and *NOT* tick_divider= ! (see http://www.centos.org/docs/5/html/release-notes/as-x86/RELEASE-NOTES-U1-x86-en.html) It seems so to work with the correct kernel parameter and so there is no need to build a kernel-vm for CentOS 5.1 guests .. (it's still needed for example for 4.x ..) Keep on reading the comments on bugs.centos.org for further informations ... I assume that upstream release notes will be corrected to reflect the real parameter -- Fabian Arrotin <fabian.arrotin at arrfab.net> Solution ? echo '16i[q]sa[ln0=aln100%Pln100/snlbx]sbA0D4D465452snlbxq' | dc -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 189 bytes Desc: This is a digitally signed message part URL: <http://lists.centos.org/pipermail/centos-virt/attachments/20080102/28335dff/attachment-0003.sig>