Is RAID1 good for performance?

[onam]

Hello,
I have 1 SSD 256GB, 2 HDDs each with 1TB. I did a software RAID 1 using only the HDD through proxmox environment. It is ZFS filesystem.
Imported a vm (4GB RAM). It uses 12GB of RAM.

I wanted to host three websites and considering each has 4GB RAM it looks like the RAM will be used fully.

Is this a good solution, because it seems to me that it does use a lot of memory to use this kind of setup.

 

[Dunuin]

ZFS will use UP TO 50% of your hosts total RAM for its ARC (read cache). But if something else needs that RAM the ARC will also shrink again.
And yes, raid1 is beneficial for performance, as you get double the read performance. Of cause not as fast as a raid0 which would also double the write performance, but thats not really the point when using raid1. Its all about not loosing your data (either bit rot over time or failed disk) and less downtime. The additional read performance of raid1 is just a nice side effect.

 

[onam]

Thanks for the reply. Where should I store these VMs? Should I get a bigger SSD, say 1TB and use that to store VM?

 

[Dunuin]

Yes, SSDs for the VM storage would be highly recommended as HDDs lack the needed IOPS performance.