Adding an SSD for caching/meta data tiering

[EKroboter]

I'm running OS 6.9.0 and have a spare 250GB SSD. Our unit has 5 3TB drives in Flex-RAID (RAID5), so I have room for one more drive. I was reading about SSD Meta Data Tiering but can't figure out if it would work on my setup. Is this only for an all-SSD RAID? Will a single SSD drive improve performance at all?

I can't seem to find any info on how to set it up.

[StephenB]

The SSD is supposed to work in conjunction with the mechanical disks (there'd be no benefit in tiering if you have an SSD array).

But I was told the tiering required RAID-1, so you'd need to install two SSDs to use it.

[EKroboter]

Thanks. So I won't be able to use it then, as I only have room for one more drive. That sucks.

[StephenB]

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@EKroboter wrote:

Thanks. So I won't be able to use it then, as I only have room for one more drive. 

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I do have two slots on my main NAS, but I'm not convinced that SSD tiering trumps saving those slots for future expansion.  It'd be helpful to see some performance measurements on how much tiering helps (and also get some guidance on the SSD size that is needed for it).