NetWorker: Device in Write Protected

Summary: NetWorker devices are in a write-protected (read-only) state. Backups or clone jobs writing to the "read-only" do not start or fail.

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Symptoms

  • Data Domain disk-volume is mounted in write-protected mode.
  • No Backups can be written to the disk.
  • The NetWorker Management Console (NMC) alerts window shows the below error.
    Error:- media Rd=xxxxxxxxx mounted Data Domain disk xxxxxxxx (write protected)

Cause

The volume is set to "read-only."

The nsrmm command shows the volume as mounted, but "write protected:"

[root@nsr ~]# nsrmm
Data Domain disk nsr.amer.lan.dddefault.002 mounted on ddve01.amer.lan_BackupDevice02, write protected

This can also be seen from the NetWorker Management Console (NMC), under Media -> Disk Volumes:
NetWorker volume is set to read only 

The volume name has a (R) suffix and shows as read-only.
 

The volume may have been manually set to "read-only" by the backup administrator. Volumes may also be set to "read-only" following a NetWorker Server Disaster Recovery (NSRDR).

Resolution

The volume must be set back to "appendable" in order to write backups. This is possible from the NetWorker server command-line or from the NMC.

NOTE: The device must be unmounted before changing the volume state.

Command-Line:

  1. Open an elevated command prompt or shell on the NetWorker server.
  2. Make not of the devices associated with volumes showing "write protected:" nsmm
  3. Umount the device: nsrmm -f DEVICE_NAME -u
  4. Set the volume as notreadonly (which means appendable): nsrmm -o notreadonly VOLUME_NAME
  5. Mount the device: nsrmm -f DEVICE_NAME -m

Example:

[root@nsr ~]# nsrmm
Data Domain disk nsr.amer.lan.dddefault.002 mounted on ddve01.amer.lan_BackupDevice02, write protected
...

[root@nsr ~]# nsrmm -f ddve01.amer.lan_BackupDevice02 -u
Unmounted device: ddve01.amer.lan_BackupDevice02

[root@nsr ~]# nsrmm -o notreadonly nsr.amer.lan.dddefault.002
Mark Data Domain disk nsr.amer.lan.dddefault.002 as not readonly? y

[root@nsr ~]# nsrmm -f ddve01.amer.lan_BackupDevice02 -m
Data Domain disk nsr.amer.lan.dddefault.002 mounted on ddve01.amer.lan_BackupDevice02, write enabled

NetWorker Management Console (NMC):

  1. Log in to the NMC as an administrative account. For example, the default "Administrator" account.
  2. Go to Devices -> Devices and unmount the device associated with the "read-only" volume. Right-click the device and select unmount.
  3. Go to the Media -> Disk Volumes tap and select the volume marked "read-only." Right-click the volume and select change mode.
  4. A window appears, displaying the modes.
  5. Select Appendable in the window, then click OK.

Changing volume mode to appendable

  1. Return to the Devices -> Devices window and remount the device. Right-click the device and select mount.

Affected Products

NetWorker

Products

NetWorker Family
Article Properties
Article Number: 000038283
Article Type: Solution
Last Modified: 09 Jan 2026
Version:  5
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