Setup a Raid5 volum...
 
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Setup a Raid5 volume with drives of different sizes

(@bhdicaire)
New Member Customer

Hello,

I just got my OWC ThunderBay 6 and I'm excited about the perspective:
* I do run a server and I need speed, safety, a flexible system
* I store work documents, computer code, virtual machines, photography, music, ...

I'll connect the enclosure to a Mac Mini 2018 with macOS Mohave with a 10G network interface. The computer will be used as a file server, network services and docker containers.

I bought 4 WD Red Pro 10 TB and a Samsung 970 EVO M.2 2TB SSD. I'll reuse two WD Red Pro 8 TB with less than 3,000 hours of use.

I installed the drives and certified them. So far so good. Do I need to update the firmware once or on a regular basis ?

Is it a good idea to setup a Raid5 volume with with drives of different sizes ? I'll use all my WD Red Pro drives (4 x 10 TB and 2 x 8 TB) to get 42 TB of available disk space supported by 14 TB of redundancy (e.g. 25%).

I'll use the SSD as a scratch disk, dedicating it to cache seem like a waste.

What file format should I use for the Raid5 and the SSD disk volume ? HFS+ (MacOS Extended Journaled) for the Raid% and APFS for the SSD?

Thanks for your help!

-- Benoit

Quote
Topic starter Posted : 07/12/2018 9:04 am
(@softraid-support)
Member Admin

Keep in mind you do not get all the capacity if the disks are dissimilar. So create a 4 disk RAID 5 with the 10TB drives, then another volume with the two extras.

If you cfreate a 6 drive RAID 5, you get 5 X 8TB or 40TB capacity and there is a spare 2TB available on the 4 10TB drives. You can do what you want on those.

Yes use the SSD as a scratch, good idea.
APFS will be 30% slower, so use HFS on the SSD.
The data volume should be HFS, (default). We do not yet support APFS on SoftRAID volumes, but when we release SoftRAID 6, we hope to address the 50% performance penalty APFS imposes on rotating media.

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Posted : 07/12/2018 12:31 pm
(@bhdicaire)
New Member Customer

Thanks for the insights :)

What if I create a 6 drive RAID 5 with 40TB capacity (5 X 8TB) AND a 4 drives RAID 5 with 6TB capacity (3 x 2TB) ? Will I get better performance than using one volume per drive size ?

I encrypt my volumes with Filevault2 is there any side efffects ?

-- Benoit

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Topic starter Posted : 09/12/2018 4:40 am
(@softraid-support)
Member Admin

RAID 5 gies you much better performance than a single disk. 4 drives, over thunderbolt, should get between 400 and 600MB/s depending on the drives.

We do not yet support encryption because of OS X limitations. This will change when SoftRAID 6 is released, then we will be able to support encrypted APFS volumes.

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Posted : 10/12/2018 9:52 am
(@mgarrucho)
Active Member

Hi, sorry to intrude, but with 4x10tb and 2x8tb, can you actually create a 6x8tb and 4x2tb of raid5? By making 2 volumes (2tb and 8tb) on each of the 10tb so you can utilise the extra space in the 10tb’s? Thanks.

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Posted : 05/05/2021 7:49 am
(@softraid-support)
Member Admin

Yes you can.

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Posted : 05/05/2021 10:15 am
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