replace raid5 disk with tw_cli

[reed at reedmedia.net]

I have done this a few times before and documented my steps before, but 
this time, I am out of luck.

Any ideas on the following?

For some reason the new physical disk was assigned to a new "unit 1".

The other three are on "unit 0".

So I deleted that unit:

	tw_cli maint deleteunit c0 u1

Then did the rescan:

	tw_cli maint rescan

That worked but it was flagged as (NO UNIT).

So I created it:

	# tw_cli maint createunit c0 rspare p1
	Created unit /c0/u1 (Unit Drive Utilization = 100%

And that put it back at u1. I don't see any docs on how to get it to go to 
u0 (unit 0) -- it is not an option in the docs and I tried it and it 
failed.

So rebuilding anyways:

	# tw_cli maint rebuild c0 u1 p1

	(0x0B:0x0031): Rebuild unit ok

And now the spare exists but it is not part of the u0 RAID5 which is still 
DEGRADED.

So this is what the system has:

# of units: 2
        Unit 0: RAID 5 894.27 GB ( 1875421056 blocks): DEGRADED
        Unit 1: SPARE 298.09 GB ( 625142448 blocks): OK

# of ports: 4
        Port 0: WDC WD3200SD-01KNB0 WD-WMAMR1568561 298.09 GB (625142448 
blocks): OK(unit 0)
        Port 1: WDC WD3200AAJS-00RYA0 WD-WMAPZ0120885 298.09 GB (625142448 
blocks): OK(unit 1)
        Port 2: WDC WD3200SD-01KNB0 WD-WCAMR2111267 298.09 GB (625142448 
blocks): OK(unit 0)
        Port 3: WDC WD3200SD-01KNB0 WD-WMAMR1461915 298.09 GB (625142448 
blocks): OK(unit 0


(The WD3200AAJS-00RYA0 is the new disk that just replaced a bad 
WD3200SD-01KNB0 originally at Port 1 and unit 0.

Here is my DEGRADED RAID5:
...
Unit /c0/u0
---------------------
Status:        DEGRADED
Unit Type:     RAID 5
Stripe Size:   64k
Size:          894.27 GB (1875421056 blocks)
# of subunits: 4

        Subunit 0:    CBOD: OK
        Physical Port: 0
        Logical  Port: 0

        Subunit 1:    CBOD: DEGRADED
        Physical Port: N/A
        Logical  Port: 1

...

I can't see in the 3ware docs how to make that p1 on u1 be on Unit 0.

I want to replace that DEGRADED Subunit 1 (Physical Port: N/A) with that 
new disk.

Any help or pointers would be appreciated.

  Jeremy C. Reed