McGarrah Technical Blog

Enabling SMART Monitoring on Seagate USB Drives

4 min read

USB drives are notorious for hiding their SMART data behind finicky USB-to-SATA bridges. If you’ve ever tried to check the health of a Seagate USB drive and gotten frustrated with “unsupported field in scsi command” errors, you’re not alone.

After wrestling with several Seagate drives in my homelab, I finally figured out the magic incantations needed to get SMART data working. Here’s how to do it properly.

Note: The decision to not allow this in Linux as a default was done for a good reasons. You are playing with fire as some drives behave erratically. I have not experienced this with recently purchased USB Drives, but older ones did have quirks and issues. So buyer beware.

The Problem

Modern USB drives use UAS (USB Attached SCSI) which should make SMART data accessible, but many Seagate drives have quirky implementations that break standard SMART commands:

# This is what you'll see initially - frustrating!
root@poe:~# smartctl -d sat -T permissive -a /dev/sdd
Read Device Identity failed: scsi error unsupported field in scsi command

Device Model:     [No Information Found]
Serial Number:    [No Information Found]
SMART support is: Ambiguous
A mandatory SMART command failed: exiting.

Sound familiar? The issue is that these drives need special USB storage quirks to work properly.

Step 1: Identify Your Seagate Drive

First, find your drive’s USB vendor and product IDs:

# Check current quirks (probably empty)
cat /sys/module/usb_storage/parameters/quirks

# Find your Seagate drive IDs
lsusb -tv | grep "ID 0bc2"

In my case, I found several Seagate models across my cluster:

Step 2: Apply USB Storage Quirks

The solution is to disable UAS for these specific drives and force them to use the older USB Mass Storage protocol. Here are three methods:

Method 1: Runtime Quirks (Temporary)

For immediate testing:

# Apply quirks immediately (lost on reboot)
echo "0bc2:ac2b:,0bc2:ac41:,0bc2:2344:" > /sys/module/usb_storage/parameters/quirks

# Verify it worked
cat /sys/module/usb_storage/parameters/quirks

Method 2: Modprobe Configuration (Persistent)

For permanent changes that survive reboots:

# Create modprobe configuration
echo 'options usb-storage quirks=0bc2:ac2b:,0bc2:ac41:,0bc2:2344:' > /etc/modprobe.d/usbstorage-quirks.conf

# Rebuild initramfs
update-initramfs -u

Method 3: GRUB Boot Parameters (Most Reliable)

This method works even if the modprobe approach fails:

# Create GRUB configuration
cat > /etc/default/grub.d/usb-quirks.cfg << EOF
# Override quirks for Seagate USB drives
GRUB_CMDLINE_LINUX="\$GRUB_CMDLINE_LINUX usb_storage.quirks=0bc2:ac2b:,0bc2:2344:,0bc2:ac41:"
EOF

# Update GRUB and reboot
update-grub
reboot

Step 3: Verify the Fix

After applying quirks and reconnecting your drive:

# Check that quirks are active
cat /sys/module/usb_storage/parameters/quirks
# Should show: 0bc2:ac2b:,0bc2:2344:,0bc2:ac41:

# Verify drive is using usb-storage instead of uas
lsscsi -H
# Look for your drive - should show usb-storage, not uas

# Now try SMART commands
smartctl -d sat -a /dev/sdX

Success! SMART Data Available

With the quirks in place, you should now see proper SMART data:

# Basic SMART info
smartctl -d sat -i /dev/sdX

# Full SMART report
smartctl -d sat -a /dev/sdX

# Health check
smartctl -d sat -H /dev/sdX

Common Seagate USB Drive IDs

Here are the most common Seagate USB drive IDs that need quirks:

If you have a different model, use lsusb to find your specific vendor:product ID.

My Multi-Node Setup

Across my Proxmox cluster, I found these Seagate drives:

Using the GRUB method, all nodes now have working SMART monitoring on their USB drives.

Understanding Quirk Flags

The quirk string format is vendor:product:flags. Common flags:

For SMART access, we typically want empty flags to force USB Mass Storage mode.

Troubleshooting Tips

  1. Still getting errors? Try unplugging and reconnecting the drive after applying quirks
  2. Multiple methods not working? Some drives need the -T permissive flag: smartctl -d sat -T permissive -a /dev/sdX
  3. Performance concerns? USB Mass Storage is slower than UAS, but the difference is minimal for monitoring
  4. Persistent issues? Check dmesg for USB errors after connecting the drive

Why This Matters

USB drives fail without warning. Having SMART data means you can:

In my homelab, I use these drives for backup storage and media serving. Being able to monitor their health is crucial for maintaining data integrity.

References

Now go forth and monitor those USB drives properly! Your future self will thank you when you catch a failing drive before it takes your data with it.

Tags: seagate, usb, smart, monitoring, storage, linux, proxmox, homelab
Categories: technical, hardware