nextcloud: move redis volume to VOL_CACHE

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

nextcloud/README.md

@@ -41,12 +41,12 @@ To test without NPM, open http://HOST_IP:8084. Set `NEXTCLOUD_DOMAIN=HOST_IP` an
 ## Volume Notes
 
     /var/lib/mysql – host path /data/nextcloud/db (MariaDB data)
-    /data – host path /data/nextcloud/redis (Redis cache, safe to lose)
+    /data – host path /var/cache/nextcloud/redis (Redis cache, file locks and sessions; safe to lose, users are logged out)
     /var/www/html – host path /data/nextcloud/data (Nextcloud app, config and user files; shared by nextcloud and nextcloud-cron)
 
     /var/www/html/data/appdata_<instanceid>/preview – host path /var/cache/nextcloud/preview (generated thumbnails; only once NEXTCLOUD_PREVIEW_DIR is set)
 
-Back up `/data/nextcloud/data` and `/data/nextcloud/db` together. Leave out `/var/cache`: previews are regenerated on demand.
+Back up `/data/nextcloud/data` and `/data/nextcloud/db` together. Leave out `/var/cache`: previews are regenerated on demand, and Redis rebuilds its cache.
 
 ### Moving previews to VOL_CACHE
 

nextcloud/compose.yaml

@@ -18,7 +18,7 @@ services:
     image: ${REDIS_IMAGE:-redis:alpine}
     restart: ${REDIS_RESTART:-unless-stopped}
     volumes:
-      - ${VOL_PATH:-/data}/nextcloud/redis:/data
+      - ${VOL_CACHE:-/var/cache}/nextcloud/redis:/data
     networks:
       - internal
 

nextcloud/sample.env

@@ -1,6 +1,6 @@
 # Compose
 VOL_PATH=/data
-# Regenerable data (previews) — exclude from backups
+# Regenerable data (previews, redis) — exclude from backups
 VOL_CACHE=/var/cache
 NEXTCLOUD_IMAGE=nextcloud:35
 NEXTCLOUD_RESTART=unless-stopped