Is there a way to migrate owncloud 7 to nextcloud 10 without affecting clients

Running owncloud 7 on ubuntu 12.04 hardware.
Need to migrate oC7 to nextcloud 10 running in a vm.

That’s not a big deal.

But. I have clients far flung across the nation, many on 1.5 mbps dsl connections, so those with a few hundred MB of data are looking at serious time and bandwidth usage to resync.

What I’d like to figure out is a way to migrate the data in such a way that when finally switching port forwarding from the oC7 to the NC10 servers a complete resync of the clients isn’t triggered though there will be a need to accept the new self signed cert.

I tried copying a file with rsync into a user directory on NC10 and NC10 doesn’t pick it up even after a reboot of the NC10 server. I know, it was shot in the dark.
greatminds was rsyncd into the directory at the command line,
ownerop3 was uploaded with the web interface.

drwxr-xr-x 2 apache apache 46 Oct 14 11:27 .
drwxr-xr-x 6 apache apache 89 Oct 14 11:23 …
-rw-r–r-- 1 apache apache 9728 Oct 14 11:26 greatminds.doc
-rw-r–r-- 1 apache apache 1133 Oct 14 11:27 ownerop3.csv

First, you need to upgrade your OC 7 up to NC 10 in order to avoid a new sync process. You can migrate your current OC 7 setup to the new system (put the old one in maintenance mode that no one changes data). Then you can upgrade.
OC 7.0.x → 7.0.15 → 8.0.15 → 8.1.10 → 8.2.8 → 9.0.5 → NC 9.0.54
you can get all version from Changelog - ownCloud and https://nextcloud.com/changelog

After each upgrade, I would login as admin and also enable all apps you are using. There are also some changes between the versions and if you turn them on you make sure they convert their data properly as well.

If you are at NC 9, I would use Nextcloud for a couple of days and not directly move to NC 10. Backgroud: in OC9.0/NC9 calDAV and cardDAV were moved to the core. Data from the old calendar and contact apps are transferred automatically (normally). The upgrade to NC 10 deletes the old tables, in case some conversion went wrong or didn’t work at all (was a problem in combination with LDAP). If you keep your old system, you can still login there and export the calendar and contacts (and reimport on NC 10), so you can also go all the way to NC 10.

You should notify your users that there will be a new private certificate and also tell them the fingerprint. There is no new sync because of a changed certificate. It would be an advantage to use your own domain for which you can use public certificates (e.g. letsencrypt). Shouldn’t cost more than $12 or 12€ a year.

I believe the underlying issue I have here with upgrading the oC 7.0.15 version is that I’m bound by php stuck at 5.3.10 and apache at 2.2.22 on ubuntu 12.04.

That’s why I’m trying to figure out a backdoor way of avoiding a re-sync with these many family members.

The rest of it, the cert isn’t an issue, nor the use of any apps, it’s just the data, hundreds of MB’s at each node and really slow connections.

You want to run the vm on your ubuntu 12.04-host? For the new vm, you should use a more modern system than ubuntu 12.04.

Indeed, that’s why I want to migrate the data from the old hardware based oC 7.0.15 to an up to date os like ubuntu 16.04 with Nextcloud 10 that just happens to be running as a vm.

I’d just like to figure out a way to do it without forcing the far flung family members to resync their clients.

But why can’t you migrate ownCloud to the new machine and then run all the upgrades?
Can you install php<7.0 on ubuntu 16.04? OC started to support php 7.0 with version 8.2. So for the upgrades to 8.0 and 8.1 you would need a system with php 5.4 or php 5.5.

Alternative use debian 8 which comes with php 5.6, do all the upgrades. In the end you can install php 7.0 from dot-deb packages.