Re: Downgrade from RAID6 to RAID5

Yes I've done it several times. FULL BACKUPS with VERIFIED results that everything is on tape. Turn off RAID6, then turn on RAID5. Takes a long time to build the RAID striping. The system will be unprotected during that time.

Assuming you cannot take the time (it'll be a full weekend depending on how much storage you have) you could hang an expansion chassis on it with sufficient disk, start RAID5 on that and migrate the system. Last step is to copy the load source. Then re-raid your original disk to RAID5, and migrate the system back if you wish to. If done that before too where I've provided the hardware temporarily to get the job done. Total down time with both load source migrations, about 5 hours.

Jim Oberholtzer
Agile Technology Architects
Office: 414-433-4363
Cell: 414-915-1445
Sent from iPad

"I've learned that courage is not the absence of fear, but the triumph over it. The brave man is not he who does not feel afraid, but he who conquers that fear". -- Nelson Mandela

On Nov 24, 2017, at 12:53 AM, Don Brown <DBrown@xxxxxxxxxx> wrote:

Hi All,

Long story short.

Have a system at 7.3 with 6 x 139GB spinning disks RAID6 and a disk write
performance issue.

As RAID6 will require three writes to update all striping and RAID5 will
need two theoretically converting from RAID6 to RAID5 should provide a
performance increase ?

There is no space for additional drives in this system - Mirrored pair are
used in Asp02

SSD's is not an option because both IBM and IBM remarketing both do not
have any of the required drives for this model 8202-E4B

We are considering second hand SSD's but not a preferred option.

Has anyone changed the RAID configuration from 6 to 5 and have any
comments on the process ?

Thanks
Don Brown


--
This is the Midrange Systems Technical Discussion (MIDRANGE-L) mailing list
To post a message email: MIDRANGE-L@xxxxxxxxxxxx
To subscribe, unsubscribe, or change list options,
visit: https://lists.midrange.com/mailman/listinfo/midrange-l
or email: MIDRANGE-L-request@xxxxxxxxxxxx
Before posting, please take a moment to review the archives
at https://archive.midrange.com/midrange-l.

Please contact support@xxxxxxxxxxxx for any subscription related questions.

Help support midrange.com by shopping at amazon.com with our affiliate link: http://amzn.to/2dEadiD