Dual Controller Failure - What Happens to the Data on Disk Shelves

NETAPPORATI — Thu, 05 Jun 2025 06:25:50 GMT

Hi All,

Touch wood, Our Netapp is still alive and kicking 🙂

This question is for knowledge / learning purpose only.

Q : Say I have a FAS3210 Dual Controller / head Configuration with 2 Disk Shelves, Say I have assigned One Disk Shelf to each controller respectively, Say I have CIFS shares on One controller (Data = 4TB) and on the second disk shelf I have LUNS mapped on Windows and Linux boxes.

Assuming I have no backups of anything on the storage ( in reality, We do practice backups as a strict procedure with test restores and backup health checks).

So :

Controller - 0 : One Aggregate (apart from the root aggregate), ONE Volume with all available space, CIFS Shares inside that volume, Data = 4TB+

Controller - 1 : One Aggregate (apart from the root aggregate), One Volume with 4 or 5 LUNS mapped to Windows or Nix Hosts.

Imagine if both controllers are dead at the same time or say after an hour of the first failure both controllers are pronounced completely dead / failed. What will or how will I recover the data on it ?

Would it be :

a) A simple case of replacing both of the failed controllers and they will magically pick up the configuration stored somewhere on the disks ?

b) How would I recover the whole storage environment with minimum downtime once the controllers have arrived, so minus the shipping time to customers facility.

Will be grateful for your suggestions / answers on this.

I am new to netapp world - in fact san world and am interested to learn more and more.

Thanks for reading !!

Re: Dual Controller Failure - What Happens to the Data on Disk Shelves

larrynce01 — Tue, 12 Feb 2013 11:27:14 GMT

Hi, probably way too late to answer this but I suspect in this scenario you would have to assign the new controller ID as having ownership of the disks then tweak some settings but essentially it would be the standard controller / head replacement procedure. After all a single head unit does not lose data in the event of a controller replacement.

topic Dual Controller Failure - What Happens to the Data on Disk Shelves in Network and Storage Protocols

Dual Controller Failure - What Happens to the Data on Disk Shelves

Re: Dual Controller Failure - What Happens to the Data on Disk Shelves