[Info-vax] MSA$UTIL experiment - try build mixed SAS/SATA drive RAID mirror set

[Chris Scheers]

Rod Regier wrote:
> As an experiment on an RX2600 with a P400 controller
> I tried building a mixed SAS / SATA RAID mirror set.
> 
> I know that the above-mentioned configuration will function fine using separate SAS and SATA drives as JBOD, so I was investigating whether a combo would work.
> 
> (Possibly handy for failed drive replacement with a SATA disk in the future
> for existing SAS-only RAID mirror sets).
> 
> It would appear either the controller or MSA$UTIL doesn't support
> mixed drive type RAID mirror sets.
> 
> I'm not insisting it should be supported (work), but does anyone have more detail?
> 
> MSA> add unit 1/disk=(1,2)/raid=1/size=130gb
> Mixed drive types are used for the creation of the unit
> Please use similar drives. Issue SHOW DISKS command to determine the drive type
> MSA> sho disks
> 
>  SATA device                                             [Disk]
>  Disk 2: bus: 1, Target id: 6, Port: 2I,  Box/Enclosure: 1, Bay: 2,  size 465.76
>  [500.11]GB
>   Disk 2, # 0, size 976707632 blocks, (465.73 [500.07] GB), Unused.
> 
>  SAS device                                              [Disk]
>  Disk 1: bus: 1, Target id: 7, Port: 2I,  Box/Enclosure: 1, Bay: 1,  size 136.73
>  [146.82]GB
>   Disk 1, # 0, size 286683952 blocks, (136.70 [146.78] GB), Unused.

FWIW:

In the x86 world, the P400 controller does not support mixed sets.  Sets 
  need to be either all SAS or all SATA.

The same applies to the P800, P410, P420, etc.

NOTE: If using SATA drives in a set, try to first confirm that the 
drives support and are configured to use TLER.  If you can connect the 
drives to a box with smartctl, use the command:

	smartctl -l scterc /dev/xxx

If they don't support it, I recommend that you use other drives or stick 
to JBOD.

-- 
-----------------------------------------------------------------------
Chris Scheers, Applied Synergy, Inc.

Voice: 817-237-3360            Internet: chris at applied-synergy.com
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