Issue/Introduction

This article helps troubleshoot mpath device in-use errors when adding ZSphere SAN data storage.

Symptoms

• Adding SAN data storage fails with can't open /dev/mapper/mpathm exclusively or Mounted filesystem.
• The multipath device is visible in the underlying system, but the platform cannot manage it as data storage.

Environment

• Product: ZVF
• Version: 4.x
• Component: ZSphere
• Affected object: SAN data storage
• Scenario: For storage and passthrough issues, confirm the current version, deployment type, storage type, and operation timeline.

Possible causes

• The filter rule in lvm.conf or lvmlocal.conf is incorrect.
• The target mpath device is used by an existing file system, LVM, or another process.
• Multipath device naming or WWID identification is abnormal.

Resolution

Perform the following checks in order, and record the affected object, occurrence time, complete error message, and current status.

1. Confirm the target LUN, WWID, mpath device, and host visibility.
2. Use read-only checks of multipath, lsblk, and pvs/vgs/lvs to confirm whether the device is in use.
3. Verify whether the lvm.conf or lvmlocal.conf filter matches the current device.
4. Before changing filter rules or releasing the device, confirm that the LUN does not carry existing service data.

Remediation

1. After confirming that the target LUN does not carry existing service data, a volume group, or a file system, correct the LVM filter rule or release the usage according to the current device plan.
2. If device references cannot be confirmed, retain multipath and LVM information and contact ZStack official technical support to confirm the remediation path.

Verification

• The target LUN is correctly identified and is no longer occupied by an incorrect mpath or LVM reference.
• SAN data storage can be added successfully, and existing service LUNs are unaffected.