Dell EMC PowerVault MD 34XX/38XX Series Storage Arrays Administrator's Guide

When a thin virtual disk is created, it is automatically initialized. However, the MD Storage Manger Recovery Guru may advise that you manually initialize a thin virtual disk to recover from certain failure conditions. If you choose to reinitialize a thin virtual disk, you have several options:

• Keep the same physical capacity — If you keep the same physical capacity, the virtual disk can keep its current repository virtual disk, which saves initialization time.
• Change the physical capacity — If you change the physical capacity, a new repository virtual disk is created and you can optionally change the repository expansion policy and warning threshold.
• Move the repository to a different disk pool.

Initializing a thin virtual disk erases all data from the virtual disk. However, host mappings, virtual capacity, repository expansion policy and security settings are preserved. Initialization also clears the block indices, which causes unwritten blocks to be read as if they are zero-filled. After initialization, the thin virtual disk appears to be completely empty.