hpacucli gives 'Max array count reach' with HP Smart Array P420i raid controller on DL360p Gen8

[Jeffrey Lane]

On Mon, May 9, 2016 at 3:26 PM, Decstasy <dj at decstasy.de> wrote:
>> Personally, I'm a little more concerned that he's running software
>> RAID 1 on top of a physical RAID 0
>
>
> I totally agree with this...
>
>
>> If one of the physical disks fails, he loses everything.  There is no
>> protection at all from failure the way he has it set up...
>
>
> As I understood he has:
> +--------+--------+--------+--------+
> | Disk 1 | Disk 2 | Disk 3 | Disk 4 |
> +--------+--------+--------+--------+
> | RAID 0          | RAID 0          | <- Via P420i RAID controller
> +-----------------+-----------------+
> |               RAID 1              | <- Via MD RAID
> +-----------------------------------+
> | Whatever Partition, LVM, FS etc.  |
> +-----------------------------------+
>
> Is this correct Asif?
>
> If it's correct, one (or two - it depends) disk can fail without a data
> loss.

Yes, that is correct.  Asif contacted me off-thread and cleared up my
confusion about the layout.  It stems from the fact that his RAID
controller apparently doesn't support JBOD.

Coincidentally, if you're going to be rebuilding and still want to
just use JBOD, a quick google search returned hits like this:

https://communities.vmware.com/thread/484114?start=0

which indicate you CAN put the controller in JBOD mode, it's just not
via an obvious config option.

To View controller config using HPSSACLI with ESXCLI
~ # esxcli hpssacli cmd -q "controller slot=0 show config detail”
To enable HBA mode on P420i using HPSSACLI
~ # esxcli hpssacli cmd -q “controller slot=0 modify hbamode=on forced"

Additionally, there is the following doc from HPE:
http://www.hp.com/ctg/Manual/c04441382

that says:
HPE Smart Array controllers support HBA mode. In HBA mode, all
physical drives are presented directly
to the operating system and the hardware RAID engine is disabled.
To enable HBA mode, see the Smart Storage Administrator User Guide on
the Hewlett Packard
Enterprise website. (http://www.hpe.com/info/smartstorage-docs)

So that second link should give you more info on the controller and
putting it into HBA mode.

(I hope).

Cheers

Jeff