Matter most import from slack channels start with bis_ and some random characters c01tg12cz7u

1

I recently did a large migration from Slack to Mattermost. I exported and imported the data in one-year increments so the computer could handle it. After finishing the report it appears most things came over great and I’m pretty happy with the process.

However, i had a few channels ran into is some channels with random character names “c02q6gtvag0” that are not Slack. These channels particularly came over with no data in them.

Any advice on these two things would be helpful.

And a bonus question here. After the import mattermost sees every channel a user is in as unread messages. Is there a quick way to mark every message read so my users don’t have to clear each channel? I’m currently running a PHP script that accesses the API and loops through each user and each channel and marks it as read. But I’m not sure yet that will handle private messages and it is taking a very long time to run

2

Hi Sheaffer, great to hear that your migration went well overall!

For the random channel names issue, this might occur if the Slack export includes system channels or archived channels with no associated data—here’s a guide to the Slack import process that might help clarify.

3

Thanks I’ve been following that guide. I was able to get a channel audit and we realized that every channel came over so we were able to delete those old channels. Not entirely sure what they were. And the bis_ was an old naming convention from before my time so those were migrated correctly.