Template: prometheus/remove-version1-database
Type: boolean
Default: true
_Description: Remove old Prometheus version 1 database files?
 The data format in Prometheus 2.0 has completely changed and is not backwards
 compatible with 1.x. On installing this upgrade, the old database files are
 moved from /var/lib/prometheus/metrics to /var/lib/prometheus/metrics.old-version-1.
 .
 If you want to delete the old data instead of keeping it around, say Yes now.
 .
 There is no conversion tool; if you want to retain access to the old data, it
 is necessary to run a separate Prometheus 1.x instance on that data directory.
