Now that we have more space, we can extend the retention time to 5 years
to hold the monitoring metrics. For a year we have:
# du -sh /var/lib/prometheus2
13G /var/lib/prometheus2
So we can expect it to increase to about 65 GiB. In the future we may
want to reduce some adquisition frequency.
Reviewed-by: Aleix Boné <abonerib@bsc.es>
Rodrigo Arias Mallo
1985b58619