PCI-E SATA II/III Adapter that Works with FreeNAS?

[Charles Elliott]

I would like to add a SSD cache to a FreeNAS box, but all the SATA ports are occupied. Does anyone know of a PCI-E adapter that offers one or two SATA II/III ports that will work with FreeNAS that is not too expensive? Motherboard is SuperMicro X9SCL-F-O, which has two PCI-E 3.0/2.0 X8 slots and one PCI-E 2.0 X4 in X8 slot.

Supermicro's claim of PCI-E 3.0 may be an exaggeration since it always seem to run at Gen 2.

Thanks in advance for your help.

 

[Ericloewe]

No such thing exists, as is plainly stated in the Hardware Recommendations Guide.

Motherboard is SuperMicro X9SCL-F-O, which has two PCI-E 3.0/2.0 X8 slots and one PCI-E 2.0 X4 in X8 slot.

That's only with Ivy Bridge CPUs.

 

[Spearfoot]

SATA PCI cards are notoriously flaky... your best bet is to purchase an LSI 9211/ IBM M1015 / Dell H200 HBA card. These are all functionally equivalent, and can be purchased used for reasonable prices from eBay.

Search the forum and you will find an enormous amount of information about these cards.

 

[melloa]

Would that increase performance in cases that the physical memory is right sized? I'd think RAM would be faster than SSD... just checking :)

 

[Spearfoot]

Would that increase performance in cases that the physical memory is right sized? I'd think RAM would be faster than SSD... just checking :)

Well, that's a good question. I zeroed in on the SATA card conundrum and lost sight of the bigger picture...

The generally accepted rule of thumb with respect to L2ARC seems to be:

• First things first... Install the maximum RAM your system supports. Don't even think about adding an L2ARC unless you've already done this.
• You probably don't need an L2ARC unless you have multiple users/processes hitting your FreeNAS system pretty hard, hard enough that your ARC Hit Ratio consistently stays below 90%.
  
• If performance still suffers after adding the above-mentioned RAM, only then consider adding an L2ARC device (SSD or NVMe based), sized no larger than roughly 4 times the size of your installed RAM.

The caveat that many new users miss is that adding an L2ARC devices consumes a certain amount of RAM for overhead. The larger the L2ARC capacity, the larger the overhead... So installing a large-capacity L2ARC on systems with an inadequate amount RAM may actually make things worse than if they hadn't added an L2ARC at all!

Hope this helps...