Re: Raid Configuration

Steve pretty much nailed it. One additional point:

YOU (meaning your company) need to decide if the risk of data loss dur to being unprotected during a RAID5 rebuild is high enough to take the performance penalty of RAID6. Obviously IF you lose a second drive during a RAID 5 rebuild it's 'where's the tape?' time. Not likely of course statistically but then someone does win the lotto now and then....

- Larry "DrFranken" Bolhuis

www.Frankeni.com
www.iDevCloud.com - Personal Development IBM i timeshare service.
www.iInTheCloud.com - Commercial IBM i Cloud Hosting.

On 12/4/2015 7:46 AM, Steve Pavlichek wrote:

RAID6 is a little slower due to 2 parity drives but better protection.
I usually recommend RAID5 with hot spare

You also have choices of Performance or Capacity option when starting
RAID. Performance option will give you 2 RAID sets and Capacity will
give you 1 set.

Here's a link to Sue Bakers parity set Techdoc
https://www-03.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/TD105880


-----Original Message----- From: Gad Miron
Sent: Friday, December 04, 2015 3:41 AM
To: midrange-l@xxxxxxxxxxxx
Subject: Raid Configuration

To the Hardware guys

a quick one:

Due to replacing 3 SSDs installed for test puposes with (the original) 3
HDDs
The BP is breaking the existing RAID5 set of 15 HDDs and is going to build
a 18 HDDs
RAID5 set (adding 3 HDDs)

My question, should we build istead a RAID6 set ?
what are the pros & cons?

This is a 8286 41A P8 machine with 18 283GB 15K discs all in the CEC
(plus 8 more in expansion 5887)
I believe that there is a EJ0P on-board controller .

So RAID5 or RAID6 ?

thanks
gad