I have a situation where a customer has maxed out all of the existing SAS ports on their system ( 2 quad port SAS HBAS). We will be adding a new Stack along with another SAS quad port HBA. Can I safely rebalance all the existing stack connections across the new card along with the existing cards? Is it reccemended to do so ? My concern is that it I were to use only the new HBA for the new stack, it would be on a single card. Any thoughts ?
Agreed a case for proactive troubleshooting. There is no hot maintenance on a controller to move source ports but it can be done in takeover mode. I do it fairly often with one node down them giveback and repeat on the partner controller. I boot to maintenance mode before giveback to make sure the ports see the disks/shelves.
Don't be alarmed by the warning that the system is in takeover and any changes will cause issues... the only commands you will run are "sasadmin shelf" and/or "sasadmin expander_map" then do a halt, boot_ontap then cf giveback on the partner.
If the they are wanting to still redistribute shelves, then I would follow the universal guide and balance out the shelves across all the available port. As always, contact NetApp support and create a ticket before doing any moves just to have support ready in case they run into trouble.
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Thank you for the reply. so the only drawback would be that the new stack is on the same card if I don't rebalance. Rebalancing is an option provided I have the proper measures in place i.e. Less then 10 shelves per stack, case open with NetApp etc.