Array vs Lun

Not the same.

An Array is the collection of drives. For example. An Apple RAID has two Arrays. One Array on each controller. You can group the individual drives in each Array to form Logical Units (LUNS). Therefore, you can have multiple LUNs associated with a single Array. When working with Apple RAIDs the Array is hidden. (Unless you look for it). With other RAIDs (ADTX, for instance) this is not the case.

Another example, more appropriate to this forum, is Metadata LUNs. You could have multiple Metadata LUNS (2 drives RAID1) on a single Array (controller).

Hope this helps.

Doug,

I would first recommend that you purchase this book: Apple Pro Training Series: Xsan Quick-Reference Guide (2nd Edition).

To answer your question. I would not mess with affinities until I really understood what was going on.

A general san with your current hardware would have the following:
1. Metadata (2 drives on the 1st controller of the 1st RAID in a RAID1 Configuration)
2. Leave the rest of the 1st controller of the 1st RAID alone.
3. Create a single LUN on each of the remaining three controllers. Leave drives #7 and #14 out of the LUN. These will automatically be used if one of the other six drives on the controller were to fail.
4. Take all three of the LUNs and put them in the same storage pool and create a single volume.

The recommended book should answer the rest of your questions.

To minimize wasted storage space purchase a third RAID with only 4 drives. This also gives you the option of having to volumes (2 drives on each controller.) One volume for uncompressed and the 2nd for compressed footage, for example. Use this 3rd just for MD. The two 10.5TB RAIDs could then be used for data LUNs and wasted doing Metadata duties.



Ernesto Sanchez
Storage Networking Product Manager
"Sharing is Good"

P: 949-861-2706
E: ernesto.sanchez@promax.com