External RAID Enclosure - What Happens When Unexpectedly Disconnected?

H

Hurin

2[H]4U
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Oct 8, 2003
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Okay, I'm thinking of making my Norco 4020 case an external RAID enclosure rather than actually putting a server into it. I've never used externally hosted arrays before unless you count dabbling in consumer-level iSCSI.

I'd be running an Adaptec 6405 into an SFF-8087 to SFF-8088 adapter bracket, and then out into my Norco 4020 with an Intel SAS expander.

Question: What happens (long-term) if I (or someone else) powers off the Norco while the main server is still up? The RAID controller would presumably freak out. And I understand that. But, upon both units being powered down and then brought back up appropriately, will the RAID controller then auto-recover and see that its arrays aren't dead?

Assuming the RAID controller's dirty cache protection (battery or capacitor+flash) works, will it then go happily along its way once its external RAID array is back? Or would I have a messy cleanup situation on my hands?

Sorry for the dumb question. But this suddenly started to seem like a poor man's iSCSI issue where you have to be very, very sure that your network is sound and always up or all hell can break loose.
 
As long as you have battery backed cache, you are fine. This setup is literally the same as internal drives, it's just you're traversing an external path. SAS is SAS (internal or external).
 
if the external box is disconnected before shutting down the master box the array might crap itself royally.


it's usually recoverable but you could loose it all.
 
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