Custom Volume Size, or CVS, is also known by other names such as Virtual Logic Volume Image (VLVI) or Virtual Logic Unit Number (Virtual LUN).

The CVS utility is used to create smaller custom sized LUNs from the remaining space in a parity group or from existing LDEVs in a Sun StorEdge [TM] 9910 or 9960.

There are some limitations to using this utility. One limitation that is not commonly known is that open-L and open-M emulations are NOT supported. One symptom that customers may call in with is a grayed out delete button used to delete an LDEV while in the window to define a customized volume size. You get into this window by clicking Virtual LVI > Volume to Space > select the CU number and hit "Next" > select the parity group and click "Detail".

If a customer says that they cannot delete an LDEV in this window because the delete button is gray, then check the emulation of the parity group. If it is an open-L or open-M emulation then the operation will not work. This will be seen on both the Remote Management Console (RMC) and the SVP. The customer should not be administering their array from the SVP.

In general, for all supported emulation types, there are other limitations which would prevent a CVS from being created. The LDEV that will be deleted to make space for the CVS volumes must not be mapped. If a LDEV is mapped then it will have a + sign in the line for that LDEV. Another item is that if 2 or more LDEV will be used for CVS, then they must be in the same parity group.

You Cannot LUSE CVS volumes.

The minimum size that a CVS volume can be is 35 Mb.

These are all contributing factors to issues creating CVS volumes.

• glenn.thoren@sun.com