As total drives count, online vs offline are per node basis, its
corect to select node for which graphs need to be rendered.
Set prometheus scrape jobs to fetch metrics from all nodes. A sample
scrape job for node metrics could be as below
```
- job_name: minio-job-node
bearer_token: <token>
metrics_path: /minio/v2/metrics/node
scheme: https
tls_config:
insecure_skip_verify: true
static_configs:
- targets: [tenant1-ss-0-0.tenant1-hl.tenant-ns.svc.cluster.local:9000,tenant1-ss-0-1.tenant1-hl.tenant-ns.svc.cluster.local:9000,tenant1-ss-0-2.tenant1-hl.tenant-ns.svc.cluster.local:9000,tenant1-ss-0-3.tenant1-hl.tenant-ns.svc.cluster.local:9000]
```
Signed-off-by: Shubhendu Ram Tripathi <shubhendu@minio.io>