4 x SSD Btrfs/EXT4 RAID Tests On Linux 4.15

[Zan Lynx]

One thing about Btrfs that some may not know is that in its RAID-1 mode it only maintains 2 copies. So if you run it across 4 drives it does not write 4 copies. It writes 2 copies onto two different devices. And it will try to balance data across all four devices, so it will often get lucky and be able to service requests on an idle device.

This means that Btrfs can write RAID-1 twice as fast on four drives as MD can.

[DrYak]

Given the red/orange color in the BTRFS status page, it makes me slightly un-easy to see mentions of BRTFS used in RAID5/6 configurations...

[coder]

Given the red/orange color in the BTRFS status page, it makes me slightly un-easy to see mentions of BRTFS used in RAID5/6 configurations...

I still use it on top of mdraid. Since BTRFS RAID is probably utilized like 0.1% as much as non-RAID, I view it as far more suspect. Plus, mdraid supports TRIM.