29.3 Cannot See NSS Devices, Pools, or Volumes

29.3.1 Connection Failure

If you cannot see your volumes or the devices associated with those volumes, you might have a connection failure. Connection failures can occur if an adapter, cable, or switch in the path between the server and the storage device fails for any reason. If there is a connection failure, repair or reconfigure the equipment.

29.3.2 NSS Tools Recognize Only EVMS-Managed Devices

If the Storage plug-in for iManager or NSSMU for Linux does not recognize a device, it might be because NSS recognizes only what the Enterprise Volume Management System (EVMS) recognizes. NSS recognizes hard drives, CD drives, DVD drives, USB drives, and Zip drives that are managed by EVMS. If your hard drive is managed by Linux Volume Management (LVM), it cannot be managed by EVMS, and NSS does not recognize it.

For NSS on Linux, whenever you reboot your system, EVMS discovers and mounts the device nodes under /dev/evms/. For example, if you use commands to create and mount a partition at /dev/sdb2/, after the reboot, EVMS discovers and mounts the partition at /dev/evms/sdb2. The iManager Storage plug-in and NSSMU work through EVMS to manage partitions, and this behavior is expected. However, if you create and mount partitions from the command line, your partitions might appear to be lost after a reboot and EVMS discovery.

IMPORTANT:If you mount pools from the command line, you must modify your mount point to the partition’s new apparent location under /dev/evms/.

29.3.3 EVMS Not Running

NSS requires that EVMS be installed and running. If it is not running, you cannot see NSS devices, pools, or volumes on Linux.

To start EVMS:

  1. Open a terminal console on the server, then log in as the root user.

  2. At the console prompt, enter


29.3.4 Pools Not Mounted by EVMS

Randomly after a crash, you might find that EVMS fails to activate an NSS pool on a server restart and the pool and its volumes are not available. Make sure EVMS is running by entering evms_activate at a terminal console prompt, then use iManager or NSSMU to manually activate the pool and mount its volumes.