How do I SSD cache my 4x4TBRaid5

[markes12344]

Currently running my Maximums IV Extreme-Z with a 1TB Samsung SSD as OS and games, while I have 4x4TB WD drives in Raid5.

I also have 2x240GB Corsair Force drives free now, as they were Raid0 for I wanna say two years (fuzzy memory) as my OS before I got the 1TBSammy.

So as you may of guessed it I would like to use the two drives as cache for my 4x4TB Raid5, I know its overkill but its what I got, n hey this is a LTT fourm, what's not overkill.
I figured ill Raid1 the 2x240GB's for safety, but how do I begin on making them cache for the Raid5?

All 6 Drives will be using the MOBO's 6 Intel ports, where my 1TB is off the Marvell Controlled port.
I need this write speed to my array to be faster than 20MB/s give or take. I understand the bigger the Raid5 array the slower write speed it will get, hence why I would like to shove a cache in it's face n get fast writes too, after all it reads at a fast 350-400MB/s

Thats all I think you need to know, but hey drop a question if you need to know more... 

Thanx
Markes12344

[Vitalius]

https://grepular.com/Disk_Caching_with_SSDs_Linux_and_Windows

>Intel Smart Response (Motherboard + CPU has to support it)

[markes12344]

So after reading up on both, I'm beginning to realise that a SSD cache may not be what I'm looking for, or is it?

What I am looking for is a partition that when I write to it, I write to it fast onto the SSD's. While when I read from the partition I'm reading off the HHD's that are in the raid. Essentially the SSD's are a cache holding the incoming files as they slowly write them onto the HDD raid.

[markes12344]

In that case I don't know of a solution.

 

SSD cache is for fast reading purposes only.

 

If what you want ultimately means fast simultaneous read/write from your HDD's, I'm afraid it can't be done due to SATA limitation of not being full duplex.

 

The closest thing to achieving it is to write to the SSD first, and upon write completion, configure a mirroring application to offload it onto the HDD array.

this is what I feared I had to do. 

Unless dose freenas / zfs would allow me to accomplish this. 

[Vitalius]

this is what I feared I had to do. 

Unless dose freenas / zfs would allow me to accomplish this. 

Yeah, FreeNAS & ZFS can do it. 

In ZFS, it uses the RAM on the system as the cache. So reads come from the RAID 5 array, unless it's in the RAM already, and writes go to the RAM then to the array.