OMV 7 on Dell R620 — Part 3: Dashboard Configuration and Monitoring

Parts 1 and 2 covered getting OMV installed and configuring ZFS, networking, and the NFS datastore for ESXi. This part is about making the OMV dashboard useful — setting up the right monitoring widgets, tracking ZFS pool health, and adding proper performance visibility beyond what the built-in dashboard provides.

1. Enable Dashboard Widgets

First login — dashboard is blank by default

When you first log into OMV 7, the dashboard loads empty. Nothing is shown until you explicitly select what you want to monitor. OMV 7 stores widget preferences server-side (unlike OMV 6 which used browser local storage), so your layout stays consistent across any device you log in from.

Log into the OMV web interface as admin.
Click the Settings (gear icon) in the upper-right corner of the dashboard.
A checklist of available widgets appears. Enable what you need:

S.M.A.R.T. Status — drive health and temperature across all physical disks. Enable this first. You want early warning if a SAS drive in your ZFS mirror is running hot or throwing errors.
Filesystem — used and available capacity across mounted filesystems.
Network Interfaces — current status and IP for each interface, including your LACP bond and VLAN xx.
System Information — CPU and memory overview. With 384 GB of RAM, this is useful for watching how much ZFS ARC has claimed.

Click Save. The dashboard reloads with your selected widgets active.

Unlike OMV 6, which saved widget preferences in browser local storage, OMV 7 stores them on the server. Clear your browser cache or switch devices — your dashboard layout is unchanged.

2. ZFS Pool Health Monitoring

ZFS pools don’t appear in the standard Filesystem widget the way a normal ext4 or XFS mount would. For pool-level visibility, use the ZFS plugin menu:

Go to Storage → ZFS → Pools.
Highlight esxi_datastore and click Tools → Details.

This shows every VDEV and drive in the pool — each mirror pair and individual disk listed as ONLINE, DEGRADED, or FAULTED, along with read, write, and checksum error counts. Any non-zero checksum errors on a drive are worth investigating.

You can also check from the terminal at any time:

zpool status esxi_datastore

# Healthy output looks like:
#   pool: esxi_datastore
#  state: ONLINE
#   mirror-0  ONLINE  0  0  0
#     sda     ONLINE  0  0  0
#     sdb     ONLINE  0  0  0
#   mirror-1  ONLINE  0  0  0
#   ... (all 5 pairs)

3. S.M.A.R.T. Drive Monitoring

If the S.M.A.R.T. widget shows “Unknown” for any drive, monitoring hasn’t been enabled for that disk yet:

Go to Storage → S.M.A.R.T. → Devices.
Select each drive, click Edit, check Enable monitoring, Save and Apply.

Do this for all 10 SAS drives. SAS drives under continuous load accumulate reallocated sectors and seek errors over time — S.M.A.R.T. is your early warning before a mirror member fails silently.

You can also query SMART status directly from the terminal:

# Run a short SMART self-test
smartctl -t short /dev/sda

# View full SMART data including temperature and error log
smartctl -a /dev/sda

4. Advanced Performance Monitoring

Built-in dashboard shows status, not performance history

The built-in dashboard gives you current state but no historical throughput, IOPS trends, or temperature graphs over time. For a storage server feeding ESXi VMs, you want more than that.

Tool	Best For	How to Install
Netdata	Real-time visual charts — IOPS, CPU per core, network throughput, ZFS ARC hit rate. Updates every second. Best overall for a lab NAS.	One-line terminal script: `wget -O /tmp/netdata.sh https://get.netdata.cloud/kickstart.sh && sh /tmp/netdata.sh` Then access at `http://<r620-ip>:19999`
Glances	Lightweight terminal or web UI overview of all system resources. Good for quick checks without a full monitoring stack.	Install via Docker Compose through the OMV-Extras Docker plugin.
Diagnostics	Built-in RRD graphs for historical network and disk I/O. No install required.	Already in OMV: Diagnostics → Statistics in the sidebar.

For this R620 setup, Netdata is the right choice. It has native ZFS support — reads /proc/spl/kstat/zfs/ directly and surfaces ARC hit rate, cache size, and pool I/O without any manual configuration.

5. Built-in Diagnostics

Even without a third-party tool, two areas in OMV’s Diagnostics section are worth checking regularly:

Diagnostics → Statistics — RRD graphs for CPU, memory, disk throughput, and network per interface. Not real-time, but shows trends over hours and days.
Diagnostics → System Logs — consolidated view of syslog, auth.log, and service logs. If ZFS throws a checksum error or the bond drops a link, it appears here.

To watch live for bond or LACP events from the terminal:

journalctl -f | grep -i bond

Next in this series

Part 4 — Stability & Verification →