Re: IBM Power Systems enhances its server and I/O options

On 2/20/2017 12:25 PM, Jonathan Wilson wrote:

> ... is a clever expander that drives the disk
> individually/independently and passes the data along to the "i"
> and/or other power/ systems.

It is exactly a SAS Expander that can be segmented by selecting mode 1, 2, or 4. Mode 1 is all 24 slots addressable, mode 2 splits them into two sets of 12 and mode 4 into 4 sets of 6. In Mode 1 we can have two RAID cards connected EACH with the ability to address all 24 drives. it gives us the redundancy we desire for IBM i.

In Mode 2, X cables can be used to connect two pairs of RAID adapters each pair controlling 12 drives. Or single cards can be used.

In Mode 4 only a single card can be connected to each of the four sets of drives and but due to port limitations this requires X Cables as well.

The KEY though for IBM i is that since it updates the firmware of the drawer via PTF if you split it into Mode 2 there would be two different IBM i partitions communicating with the drawer and thus both of them could update it. One of them may not be ready for that new firmware! (It may be on an older release for example) And that would be a problem! So to eliminate this issue mode 1 is required and thus only one IBM i partition can possible update that firmware. No Problem!

As to your commend that you never update firmware on any other adapters etc. Good that's worked for you!! :-) Often it does not...


- Larry "DrFranken" Bolhuis

www.Frankeni.com
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