SSD in storage array?

[DarB]

Hi All, first off - my apologies if this topic has been covered already. I have an array configured as follows:

Parity - 10 TB HDD

Drive 1 - 8 TB HDD

Drive 2 - 6 TB HDD

Drive 3 - 4 TB SSD

plus 120 GB SSD for cache. 

I read somewhere the other day that you should not use an SSD in your array and I am wondering (A) is this true and why? and (B) should I change out drive 4 for an HDD and if I do, could I use that 4TB SSD for storing my VM's and what is the best method to do so?

 

Just looking for some thoughts here. 

Thanks!

[JorgeB]

You can use SSDs in the array, just need to be aware of the limitations, mainly, write speed will be limited by the parity spinner, TRIM is not supported, reads speeds will still be fast, so depending on the use case it may still be a good option.

[DarB]

5 minutes ago, JorgeB said:

You can use SSDs in the array, just need to be aware of the limitations, mainly, write speed will be limited by the parity spinner, TRIM is not supported, reads speeds will still be fast, so depending on the use case it may still be a good option.

That makes sense - thanks! 

[_cjd_]

Also yes, you could swap it out and then use it for VMs. I have an nvme I use for docker/VM and a separate set of SSDs as write cache (also primary storage for files needing fast access, backed up to the main array)

[aburgesser]

Unless you are at capacity, I would use the SSD as a secondary pool and back it's data up to the array. You don't compromise its write speed/features and you avoid exotic problems from an atypical configuration.

[DarB]

On 8/4/2024 at 11:01 PM, aburgesser said:

Unless you are at capacity, I would use the SSD as a secondary pool and back it's data up to the array. You don't compromise its write speed/features and you avoid exotic problems from an atypical configuration.

That is exactly what I ended up doing, just seemed the most logical way of going about it.