BTRFS on Hardware RAID (LSI/Avago controller)

BTRFS
1

I’m curious on the functionality and capability of BTRFS when used with a hardware RAID (MegaRAID) controller. What works better, what works worse, or what is unavailable, or unchanged…

I know in comparison to ZFS they actually recommend NOT using hardware RAID, and I’ve done some research on ZFS to understand a bit why, but I don’t fully understand where BTRFS sits in comparison.

My ultimate goal for choosing BTRFS is protection against data degradation/bit rot, so my question is mostly geared towards how BTRFS is affected in protecting against bit rot when used with a hardware controller.

2

Set Controller to Passthrough. Easy peasy.

There is no gain in speed to use BTRFS on HW controllers except Areca in JBOD as far as I know. You can use BTRFS on HW controller, but the self-heal part will not be working as intended.

Reason for Areca card: only card I know which utilizes onboard cache while JBOD mode.

3

Thanks, but I’d rather just not use the card and sell it than use it in passthrough mode (it was expensive). It would also be faster on its RAID and parity calculations than BTRFS alone as it has its own dedicated dual core processor and 1 GB RAM.

I was hoping I could still use it and its features and get self-healing somehow…

4

Sorry, the selfhealing part is integrated in how the raid function works. HW raid may have some selfcorrection, but not of the same quality as ZFS/BTRFS.