Has anyone had any experience of rolling back an Episerver instance to a previous version? I need mirroring and its unsupported above 7.5?
Mirroring is supported in the recent versions, too. It's just not that easily installable. Check out he documentation: http://world.episerver.com/documentation/developer-guides/CMS/Deployment/mirroring2/
"Note: You can install mirroring only on Episerver CMS 7.5 (through the Deployment Center). If you want mirroring with the latest Episerver version, install a CMS 7.5 site with mirroring, and then upgrade to the latest CMS through NuGet because there is no NuGet package for mirroring functionality; it is installed as a separate service in a virtual directory on the server. An updated DLL is available in the EPiServer.CMS.Core NuGet package (packages/EPiServer.CMS.Core.9.0.0/tools/MirroringService/), which you must manually patch to support CMS 10."
Unfortunately running mirroring on version 9.7 would make the installation technically unsupported, that is to say "not supported by episerver", and our client is a ftse 100 company, and so will not use unsupported software. Our only option is to roll back to 7.5, which IS supported, thus leading to my question.
I'd suggest you contact someone from Episerver (perhaps your sales contact can hook you up with someone) regarding this before going into this, I wouldn't say that mirroring is "not officially supported by Episerver", otherwise it wouldn't be in the documentation for the latest versions.
Rolling back is not officially supported and it can be pretty challenging with DB changes as well as breaking changes from 7.5 until 9-ish you have. Easiest solution is to start a fresh installation of 7.5 and copy paste your code.
Would i be able to connect up to the current database? There are hundreds of man hours putting in content and getting it approved. It is not possible to repopulate the site contents from scratch.
Ah, I didn't know you have the content there already.
You might be good with trying a quick POC where you install Epi 7.5 and copy the content models (with content GUID included). Then try to export/import content already there in 9, that is not "officially" supported between versions, but since it's the same principle behind (not like the difference between 6 and 7), it might work with perhaps small issues around custom properties, if you have any.
I think at this point you should contact support as well, maybe they have a "revert" script or a better idea.
My boss is currently contacting the UK sales director to try and find a solution, so that may throw up more information. However your idea of importing content from one instance (without mirroring) to another (with mirroring) very interesting - perhaps this will work. I cannot download version 7.5 from nuget - the Episerver.cms package is not there - the lowest i can get is 7.6.3 - do you think that will be okay?
I didn't think of importing with mirroring, I think that could potentially lead to unpredictable issues. I was thinking about export/import functionality between the site you currently have on 9+ and the one you could install from the scratch locally, ex. So, I would install the fresh site on 7.5, copy just the content models to the solution (for test sake), then export and import (at least parts of the tree, since you might get a timeout otherwise, if you try to export everything under root page). That would give you a quick overview of whether this is possible or not.
You can use Episerver deployment center to install the fresh site instead of using nuget or VS extensions, since you can't downgrade them easily either.
// I still think mirrorring is supported in 9, but it's good to get an official answer from Epi on it, ofc :)
The Episerver Deployment centre will not let me deploy an older version, will it?
You might be talking about the actual deployment?
I am referring to using this piece of software locally: http://world.episerver.com/documentation/Items/Developers-Guide/Episerver-CMS/75/Deployment/Deployment-Center/
You can download it here: http://world.episerver.com/download/Items/Download-EPiServer-75/
Oh sorry you are correct - doh!