Re: LPAR Placement of 720 Base Raid Controller

[DrFranken <midrange@xxxxxxxxxxxx>]

First the PCIe card based SSD you reference is no where near as fast as 
current SSDs because those cards had no cache. Also they required a 
system power down to replace a failed SSD so not at all my favorite or 
recommended option anyway. Good that you've ruled them out.

Second the internal RAID cards are 3Mb SAS Speed and no where near fast 
enough to 'keep up' with the SSDs. That said they will do OK with just 
four of 'em and certainly be faster than 4 spinnies in there. You have 
to make the call whether the additional investment of two RAID cards and 
a drawer to pull even more performance is too mucha da monya.

As to mixing some direct attach and some virtual storage for an LPAR, 
hmmm, I wouldn't put that first on my list of 'configuration 
recommendations' :-)  I do see how you are trying to get the most from 
the SSDs and the configuration will work but boy would it be easy to 
make-a-mess with that!

Sue Baker can likely be more specific on performance limitation of the 
SSDs in the CEC.

        - Larry "DrFranken" Bolhuis

www.frankeni.com
www.iDevCloud.com
www.iInTheCloud.com

On 1/10/2014 10:42 AM, Kirk Goins wrote:

> *I can't put the PCIe card based SSD inside the CEC*
>
> Current Setup
> 8202-E4C 6core.
> IBM i Hosting partition with several guest IBM i partition.
> Current Base Disk Backplane in the CEC does NOT support Raid
> NO Disks in the CEC
>
> Thinking of doing the following.
> Upgrading the CEC Disk Backplane to the one that supports Raid
> Install 4 SSDs on the new backplane ( ie in the front of the CEC )
> Assigning Disk Controllers Directly to one of the Guest parititions
> So it will see them as SSDs not just some other Virtual Disk.
>
> Larry, Pete or anyone else see any issues with this setup?
> Really don't want to spend upwards of $10K for a pair of 5805's and an
> EXP24s
> for just 4 SSDs