Is there any way to flash the card or something?
I am not aware of any. The information I am reasonably certain of, via hearsay, or know from direct experience, I stick into that sticky that I referenced. If you discover a way to flash a 2108 to something that supports an HBA mode, provide a link and I will certainly look at it.
Haiz, the card is more expensive than the normal HBA.
Ah, yes, the irony. I feel your pain.
FreeNas has put the card in the supported card without any warning.
The documented Hardware Recommendations clearly states:
NOTE: instead of mixing ZFS RAID with hardware RAID, it is recommended that you place your hardware RAID controller in JBOD mode and let ZFS handle the RAID. According to Wikipedia: "ZFS can not fully protect the user's data when using a hardware RAID controller, as it is not able to perform the automatic self-healing unless it controls the redundancy of the disks and data. ZFS prefers direct, exclusive access to the disks, with nothing in between that interferes. If the user insists on using hardware-level RAID, the controller should be configured as JBOD mode (i.e. turn off RAID-functionality) for ZFS to be able to guarantee data integrity. Note that hardware RAID configured as JBOD may still detach disks that do not respond in time; and as such may require TLER/CCTL/ERC-enabled disks to prevent drive dropouts. These limitations do not apply when using a non-RAID controller, which is the preferred method of supplying disks to ZFS."
My
sticky in this forum states:
The IBM ServeRAID M1015, crossflashed to IT mode, is probably one of the best choices available if you need a bunch of extra SATA ports. It does take an extra ~12 watts however. Don't buy it new. They're available cheap on eBay all the time.
Random RAID controllers that are operating in RAID mode (showing virtual or logical devices to FreeNAS) are a very bad idea. If your controller costs more than a few hundred dollars, it may not be a good choice for FreeNAS.
So I am going to say that your claim of "without any warning" is also demonstrably untrue. I will gladly concede, however, that the learning curve here is high, and that it is easy to miss these details. One normally assumes that the pricier, more capable product is the better choice. This isn't always true, and that's what prompted me to write that sticky.
The problem is that there is hardware that works, and there's the hardware that works best. From a high level point of view, ZFS is your RAID controller. It has access to eye-melting amounts of memory and CPU resources. When you put a dinky little "hardware" RAID controller after ZFS, you aren't getting anything of value from it, and you may be losing things, even, such as the ability to speak SMART with the drive.
However, let me also say this: the 2108 will work. It isn't the best pick though. You should thoroughly read the section of the LSI sticky in this forum, and you'll get most of what you "need to know." The most important bit is that the LSI will throw an LSI label on the disk and I'm pretty sure you won't be able to migrate the disks to a non-LSI controller if ever you might need to (like if the LSI controller starts on fire and you have no spare).