Update README.md

Added extra explanations.

1 files changed, 22 insertions, 6 deletions

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@@ -53,19 +53,35 @@ $ screen -r
 
 ### Update
 
-#### Using *screen* highly recommended
+##### Please use screen as the upgrade process can take a long time!
 
-`$ sudo yunohost app upgrade mastodon -u https://github.com/YunoHost-Apps/mastodon_ynh --debug `
+#### A note about backups
 
-Upgrading from 3.5.3 to 4.1.2 directly has not been integration-tested. It is recommended to do a two-step upgrade:
+First of all: Mastodon uses a local cache to save media (such as posted images, videos etc.). This cache can grow huge. 
+You could consider cleaning up your local cache first as otherwise your backup will be very big and you might run out of disk space:
+
+To check your space usage, on a command line run:
 
-Mastodon can grow huge. You could consider cleaning up your local cache first as otherwise your backup will be very big:
+`$ sudo cd /var/www/mastodon/live && sudo -u mastodon RAILS_ENV=production PATH=/opt/rbenv/versions/mastodon/bin bin/tootctl media usage`
 
-`$ sudo cd /var/www/mastodon/live && sudo -u mastodon RAILS_ENV=production PATH=/opt/rbenv/versions/mastodon/bin bin/tootctl media remove --days=0 --dry-run`
+If your cache is too big to backup, you can run the following command to clean up Attachments (the first line). Substitute X by the number of days you want to keep, e.g. 1 day. All older images will be deleted but will be refetched from the original server if necessary.
+
+First dry-run to see how much space is freed up (without actually removing):
+
+`$ sudo cd /var/www/mastodon/live && sudo -u mastodon RAILS_ENV=production PATH=/opt/rbenv/versions/mastodon/bin bin/tootctl media remove --days=X --dry-run`
 
 If all looks good commit the cleanup:
 
-`$ sudo cd /var/www/mastodon/live && sudo -u mastodon RAILS_ENV=production PATH=/opt/rbenv/versions/mastodon/bin bin/tootctl media remove --days=0 `
+`$ sudo cd /var/www/mastodon/live && sudo -u mastodon RAILS_ENV=production PATH=/opt/rbenv/versions/mastodon/bin bin/tootctl media remove --days=X `
+
+##### Upgrade
+
+The actual upgrade can be done using the following command:
+
+`$ sudo yunohost app upgrade mastodon -u https://github.com/YunoHost-Apps/mastodon_ynh --debug `
+
+
+Upgrading from 3.5.3 to 4.1.2 directly has not been integration-tested. It is recommended to do a two-step upgrade:
 
 First upgrade to 4.0.2~ynh2: