Kinda Late to the Party

[Lioninstreet]

As noted, I'm not an early adopter....

I'm setting up a "new" HP ex490 build using WHS11, fully updated using WSUS/WHS11. Storage is with four 1.92 tb SSD'd, all are now formatted and seen by the OS console. 

Starting with a noob question:  When setting up SBDP v2.2.5, is the SSD add in required or optional?

What functionality does it add?

[gtaus]

If I understand you correctly, you want to know what advantage adding an SSD to DrivePool v2.2.5 would add to your setup.

In your case, since all your pool drives are already SSDs, I don't think you would see any advantage to designating an SSD as a front end cache because all of your SSD drives probably have about the same read/write speed.

In my setup, I have 19 USB 3.0 HDDs as Archive Drives (much cheaper, but also much slower, than SSDs) and then I added a single ~250GB SSD as my front end cache for DrivePool. When I write a file to DrivePool, it first goes to my SSD (very fast) and latter when DrivePool "rebalances" it moves the files off the SSD to the much slower Archive USB 3.0 HDDs in the background. In my case, the SSD front end cache significantly sped up my DrivePool writes. If the file(s) is still in the SSD cache when I read it, it will also speed up the read process. However, by the time I want to read any of my files in DrivePool, they are almost always flushed to the Archive drives by then so my read speeds are limited by the transfer rate of my USB 3.0 HDDs. I use my DrivePool primarily as a home media storage server, so the speed of my read rates are not critical. The SSD front end cache allows to me quickly transfer files to DrivePool and then move on to some other tasks.

If, at some point, you decided to add non-SSDs to your DrivePool as Archive drives - to save money, maybe - then you would see an advantage to designating one or more of your SSDs as a front end cache for DrivePool. That way, if you write a file to DrivePool, it will always go to the SDD front end cache first at SSD speed. If not, DrivePool will attempt to balance the pool drives and maybe write directly to your Archive drive(s) at their non-SSD rated speed - which would be much slower than your SSD drives. I only mention this because my DrivePool storage continued to expand beyond my initial setup and I bought non-SSDs to save money.

 

[Lioninstreet]

@gtaus, You're correct, all the drives I'm using are SSD's so as you wrote, no reason to use the SSD Optomiser. Thanks for the advise