Sorry, I don't use CentOS 6 now so I cannot check, but: Could it be that RHEL6 changed the default superblock mdadm is creating? CentOS 5 is creating a 0.9 superblock. Some "other OS" are creating 1.2 per default. But you can change that on the command line. If that's the case it's not a bug but a feature.. GS -- Gerhard Schneider Institute of Lightweight Design and e-Mail: gs at ilsb.tuwien.ac.at Structural Biomechanics (E317) Tel.: +43 664 60 588 3171 Vienna University of Technology / Austria Fax: +43 1 58801 31799 A-1040 Wien, Gusshausstrasse 27-29 http://www.ilsb.tuwien.ac.at/~gs/ -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 253 bytes Desc: OpenPGP digital signature URL: <http://lists.centos.org/pipermail/centos/attachments/20110211/75c4c6ec/attachment-0005.sig>