About Provisioning on EMC Symmetrix Storage Systems

EMC ships its Symmetrix storage system with volumes already created. When the software first discovers an EMC Symmetrix storage system, it assumes the devices on the Symmetrix storage system are volumes.

This software refers to the term “device” to define a piece of hardware in the storage network. EMC uses the term “device” to refer to a volume on one of its storage systems. In this section, the term “device” is used in the context of EMC storage systems.

When you use the software's “create a volume” feature, you are assigning the already created volume. If necessary the software will create a meta device, which is a device that is a concatenation of several devices.

The software does not delete the volumes created by EMC. When you use the software's “delete a volume” feature, the software marks the volume as hidden in its repository. These “hidden volumes” are stored in the “Free Device” list. If you use a device in the “Free Device” list when you create a volume, that device is removed from the “Free Device” list.

Process Has an Exclusive Lock Message

The Symmetrix storage system can become locked for many reasons. For example, the storage system becomes locked when it performs LUN mapping, LUN masking or Discovery Data Collection. The Symmetrix storage system may also remain locked after a provisioning operation has failed. You will receive a message resembling the one shown below if a process has already locked the EMC Symmetrix storage system and you attempt a process that requires a lock on the storage system.

SYMAPI routine SymDevMaskSessionStart failed with error code 188: The operation failed because another process has an exclusive lock on the local Symmetrix

After the management server has detected the lock on the Symmetrix storage system, it tries to access the storage system for 15 minutes and logs the errors.

If you receive the error message, determine whether someone is performing an operation that requires a lock, such as LUN mapping, LUN masking, or Discovery Data Collection. This applies even if one of the processes is being used by a third-party product, such as for LUN masking. If this is the case, wait until the process is complete. Remove the lock manually only if you are certain that no other processes are happening on the storage system. To learn how to remove the lock, refer to the documentation for the Symmetrix storage system.

If a provisioning failure causes the Symmetrix storage system to remain locked, you are alerted to this situation in Event Manager and on the Properties tab. You may receive a message similar to the following:

Unable to end device masking session. Symmetrix '000001835005700' may be locked.

Some EMC Volumes, Their LUNs and LUN Maskings Are Hidden

EMC volumes, their LUNs, and LUN maskings for the volumes that play a special role (such as holding device masking information, attached BCVs, and gate-keeper devices) are hidden. On the host side, the software shows LUN maskings for these volumes. So you may see a LUN masking, but not its volume, residing on the EMC storage system.

HP Storage Essentials SRM 6.0 User Guide 565