Re: "Virtual" RAID1

[U'll Be King Of The Stars <ullbeking%andrewnesbit.org@localhost>]

On 24 June 2019 09:38:17 BST, tlaronde%polynum.com@localhost wrote:
>RAID1 puts an equal burden on both disks

Is it really equal?  It doesn't depend on implementation?

>you will spend your time replacing disks praying that they
>not both die at the same moment.

This is one argument for not mirroring SSD's.  I'm not sure how useful it is or if this problem really happens.  I know one person who says it does and has experienced it.

Maybe with two SSD's RAID0 is better?  Or four SSD's with RAID10?

I am pretty sure schemes like the ones you have decided have been investigated.  Maybe they already exist in some volume management systems?

I would suggest asking around in some technical, storage-related mailing lists.  Linux has a lot of these.

This is a very complicated problem.  Not only that, but I'm not sure NetBSD is a great OS for this.  What are your options for filesystems, disregarding the RAID part?

Illumos or FreeBSD might be good.

I still don't understand the problem you are trying to solve.  Is it to improve longevity of RAIDed disks?  Or do you need a fast local tier that is a subset of your full data set?

Andrew