​👈​ All-SSD server...cache R10, or risk array parity / no trim?

[Rob SFO]

My server only has SSDs.  I have a lot of them and there's no reason for me to spend money/power on mechanical disks (and it's 2021...disk is dead).

 

I have a single M.2 1TB NVMe drive, and a whole bunch of SATA SSDs (that do support TRIM). 

 

I currently have my server setup with the NVMe as cache, and 2 x SATA SSDs for the array (no parity yet).  I'm ready to add in the rest of my SSDs & protect them but I've been holding back as I research the all-SSD array issues.  

 

At this point, I am thinking I should just build a R10 cache from all the SATA SSDs, and use the NVMe as an unassigned device for VMs.  Does that sound like a good plan?

 

I'm assuming that I can simply add the SSDs to the cache, then once built I can remove the NVMe?  Will that work?  

 

I then have to migrate the data from the array to the cache, then remove/destroy the array and add those final 2 drive to the cache R10.  Any tricks to doing that?  

 

Anything I'm not thinking of?

 

### EDIT ### 👈

 

Do I have to have at least one array drive?  Can UNRAID function without an array?

I guess if I have to I could add an old piece of spinning rust that I have (4TB) and maybe use it as a backup target for the NVMe VMs?

 

Thanks!

 

Edited February 4, 2021 by Rob SFO

[Vr2Io]

1 hour ago, Rob SFO said:

I guess if I have to I could add an old piece of spinnin

You could add a USB stick as array disk and simple not use it. For best performance, you should use UD to mount R10 and NVMe.