Am 29.07.19 um 22:27 schrieb Guilherme G. Piccoli: >> If that's correct, then this seems to be a critical weak point in cases when >> we have a RAID0 as a member device in RAID1/5/6/10 arrays. > > Hi Roman, I don't think this is usual setup. I understand that there are > RAID10 (also known as RAID 0+1) in which we can have like 4 devices, and > they pair in 2 sets of two disks using stripping, then these sets are > paired using mirroring. This is handled by raid10 driver however, so it > won't suffer for this issue. > > I don't think it's common or even makes sense to back a raid1 with 2 > pure raid0 devices. if i would have been aware that RAID10 don't support "--write-mostly" to make a hybrid HDD/SSD RAID (https://www.tansi.org/hybrid/) i would likely have done exactly that to buy only 2 instead 4 x 2 TB SSD disks here and frankly i have another 5 machines where this limitation of RAID110 on linux sucks -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel