...building hybrid clouds that can support any device from anywhere
In this post I’ll examine a specific issue in Storage Spaces while using with Enclosure awareness.
1. Create Storage Pool in a cluster.
2. Use IsEnclosureAware flag to enable the Storage Space enclosure to be more resilient.
3. Connection to Storage Pool fails when either one of the Enclosures (e.g., Enclosure 2 here) is switched off.
With Windows Server 2012, a majority of drives need to be available for the pool to be online. In a case where you have two enclosures and an equal amount of drives in each, a majority of drives will not be online if one enclosure is going offline.
Using three enclosures will address this since a majority of drives will be online even in the event an enclosure goes offline.
· Enclosure Model Used: http://www.aicipc.com/ProductDetail.aspx?ref=XJ3000-2242S
· SAS Controller Model: http://www.lsi.com/products/storagecomponents/Pages/LSISAS3801E.aspx
I would have thought that since half of the mirror stays up that Storage Spaces would be smart enough to keep the pool up as all the data is still online and available...
This explanation is not very clear at all. Why is a majority of drives necessary for a two-way mirror when it's a 2:1 ratio? If that's the case, this suggests that if you simply put another some random extra disk in the second controller, it would stay online. If that's true, the requirement seems totally arbitrary.
Could you please explain *why* this is a requirement? It would help people understand the technology better. It's so promising, but because we're left on our own as to the actual hardware implementation, one typically encounters these types of situations by accident (this is not in all the documentation). At that point, the "inexpensive commodity hardware" suddenly starts becoming a lot more expensive. It's often not possible to budget for those types of mistakes.