We have a production system running Scalix 11.3 on a CentOS 5 server. We are moving to new hardware and I will use CentOS 7 plus the latest version of Scalix. I know that you can not upgrade in one step, that you have to upgrade to 11.4 first (http://www.scalix.com/forums/viewtopic.php?f=46&t=75136). I have also read this comprehensive guide to upgrading from 11.4: http://www.scalix.com/forums/viewtopic.php?f=46&t=75144#p161088.
My plan was to install Scalix 11.3 on the new server, move the data over from the live server then upgrade 11.3 to 11.4, 11.4 to 12.5. But I am having trouble installing 11.3 - it doesn't find the sasl library files despite the packages being installed. For example, on the old server I have libcrammd5.so.2 which links to libcrammd5.so.2.0.22. On the new server I have libcrammd5.so.3 which links to libcrammd5.so.3.0.00. The version of the sasl rpm on production is 2.1.22. I found the RPMs for that version but I had trouble installing them because the newer version (2.1.26) was required for other software installed on the server (sendmail and openldap). I tried copying over the contents of /usr/lib/sasl2 from the production server to test but the installer still says it needs, for example, libcrammd5.so.2 which is present. Should I be able to install Scalix 11.3 on CentOS 7? I should mention I had to edit /etc/redhat-release to fool Scalix into thinking it was RedHat Enterprise 5, so I accept that the answer might be no.
Will I have to upgrade the existing production server and then migrate to the new server in a separate step? The thing I don't like about that is the inability to do a dry run. I suppose I can find an old PC, install CentOS 5 and practice the upgrade on that, but if I could install 11.3 directly on CentOS 7 that would be by far the best option. A dry run on an old desktop PC won't give me any idea of the time it will take when I do it for real, and I need to be able to tell my boss and my colleagues roughly how long they will be without email.
One last question. If I upgrade the production server from 11.3 to 11.4 and something goes wrong, what is the rollback procedure? Which folders do I need to backup before I start and then restore to revert to 11.3?
Thanks in advance!