Hi Wolfgang! On Fri, 9 May 2025, at 9:03 PM, Wolfgang Breyha wrote: > Hi! > > I'm currently using a large cyrus 2.5 murder setup with 3 frontends, a > mupdate master and >10 backends. > > I plan to stick with > mailbox_legacy_dirs: 1 > unixhierarchysep: 0 > altnamespace: 0 > hashimapspool: 1 > fulldirhash: 1 > > The patches to correctly detect newer cyrus backend versions are in place. > > Looking into the upgrade documents of 3.x I see that "in place" upgrades > are not recommended for cyrus >3.4 in case of 2.5. > > Would it be possible to place 3.8 backends into the existing setup and XFER > the mailboxes without the issues raised by an in place upgrade? Or should I > use 3.4 as well?
This *might* work. As I recall, the big issue with in-place upgrades across the 3.4->3.6 boundary is the rewrite of mailboxes.db that happens on first startup. Older versions didn't guarantee the information required by the rewrite was present, and if any mailbox is missing it, the rewrite will fail and the upgraded server might be unable to start, or start in a weird state. Upgrading to 3.4.4+ first, running it for a while, and fixing anything that it reports as broken, gets you into a good position for a later upgrade to 3.6 or 3.8 to succeed. But if you're building new 3.8 backends and XFERing mailboxes into them, this won't apply, since the new mailboxes.db will start empty. So the questions then become: • whether 2.5->3.8 XFERs can succeed reliably; and • whether a 3.8 backend can play nicely in a 2.5 murder during the cutover period I don't know the answers, but I don't know them for 2.5->3.4 either. Perhaps some other murder users could chime in. I'd suggest reading through all the release notes for murder- or XFER-related bugs and fixes; I'm sure there have been some over the years, but I've forgotten their details. Probabilistically speaking, I think the safer bet is to get the whole deployment to the latest 3.4 first, and then move forward to 3.8 afterwards. > Or is the recommendation to use 3.4 bound to some features and upgrading to > 3.8 possible in certain cases? I at least tried it on a small cyrus 2.5 > setup without visible troubles. The devil is really in the data here, rather than the configuration. Anecdotally, it seems like the biggest difficulties come from mailboxes that have been around for a long time, especially if this 2.5 environment was previously upgraded from 2.4 or earlier, and mailboxes that were around back then are still active. Small scale testing tends to happen with new, small mailboxes, on newly-installed servers, and this doesn't reflect reality particularly well. If it were me, and if I had the resources to do so, I would want to get snapshots from some of my real servers -- at least one frontend, at least one backend, and mupdate -- and then spin up virtualised clones to test the various upgrade paths with real data. See what problems shake out, and work out how to address them. Rinse and repeat with fresh snapshots until I'm confident, and only then start touching the live servers/mailboxes. Cheers, ellie ------------------------------------------ Cyrus: Info Permalink: https://cyrus.topicbox.com/groups/info/T6b93ab144d6e9957-Me3e7c8c99a7f1f0ff50e3b94 Delivery options: https://cyrus.topicbox.com/groups/info/subscription
