grafana(host): account in Prom. hyperv. disk alerts for longer backups

Set duration for Prometheus hypervisor disk rw rate and hard disk io
alerts to 2h to account for the very long running (over 90m) backup job.

resources/chaosknoten/grafana/docker_compose/prometheus_alerts.rules.yaml

@@ -166,7 +166,7 @@ groups:
       # Longer intervals to account for disk intensive hypervisor tasks (backups, moving VMs, etc.).
       - alert: HypervisorHostUnusualDiskReadRate
         expr: (sum by (instance) (rate(node_disk_read_bytes_total[2m])) / 1024 / 1024 > 50) * on(instance) group_left (nodename) node_uname_info{nodename="chaosknoten"}
-        for: 90m
+        for: 2h
         labels:
           severity: warning
         annotations:
@@ -174,7 +174,7 @@ groups:
           description: "Disk is probably reading too much data (> 50 MB/s)\n  VALUE = {{ $value }}"
       - alert: HypervisorHostUnusualDiskWriteRate
         expr: (sum by (instance) (rate(node_disk_written_bytes_total[2m])) / 1024 / 1024 > 50) * on(instance) group_left (nodename) node_uname_info{nodename="chaosknoten"}
-        for: 90m
+        for: 2h
         labels:
           severity: warning
         annotations:
@@ -256,7 +256,7 @@ groups:
       # Since hard disks on the hypervisor can easily have their IO saturated by hypervisor tasks (backups, moving VMs, etc.), alert when the IO is above the regular threshold for a very long time.
       - alert: HypervisorHostUnusualHardDiskIo
         expr: (rate(node_disk_io_time_seconds_total{device=~"s.+"}[1m]) > 0.5) * on(instance) group_left (nodename) node_uname_info{nodename="chaosknoten"}
-        for: 90m
+        for: 2h
         labels:
           severity: warning
         annotations: