Wednesday, 28 March 2012

Storage Spaces

Based on this MS blog post, once you lost a storage space configuration, it is just lost.

At the moment, there is a significant difficulty recovering JBODs automatically. What the Storage Spaces subsystem does is, in effect, creation of JBODs of 256MB blocks. So in the end you can have just a plain JBOD, RAID 1 over JBODs, or RAID 5 over JBOD configuration. The capability to put 256MB blocks back into the pool and then use them again as needed, probably for another volume, leads to fragmentation on the pool level. That is, the volume itself gets fragmented, and obvously alignment gets out of window.

This means no RAID recovery on Storage Spaces unless some significant breakthroughs are made. Even simple volumes will not be recoverable if they got fragmented.

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