I have the possibility over the next month or two of examining the upgrading Koha from 3.8.24 to 19.11 (latest stable release.) We have the hardware available, but have a couple of questions before I plan the workflow: a) database migration? I have looked at the schemas, and am worried that there are substantial changes. Our production servers contain some 250,000 items. We are not a lending library, so have no concerns with that side of library management -- only with pure cataloguing, for which we use over 100 custom reports, 900 "sources", ten customized biblio frameworks, etc -- how best to proceed? Is there a script (or multiple scripts) that would do it? b) server software? does "pure" Debian (which we have never used in production) have advantages over Ubuntu LTS (with which we are extremely comfortable)? c) We normally build from tarballs, but have received some criticism in the past. The reason is that once we have a server locked into production, we never (major security excepted) touch it; our 3.8.24 has now been running for 1,467 days without rebooting, and "if it ain't broken, leave it alone." Is the final installation package/tarball identical using the different methods? Thanks in advance for your advice. Season's greetings, Paul