tgeng

Thanks! So the only way is to transfer the data and reformat it?

tried to swap them and i was able to start the array. but i really don't want to move all the data... the weird thing is that the command `hdparm` shows the same size i'd better cancel the order for another two 860 evo, since the tiny difference. thank you for the reply!

I have two Samsung 860Evo 2TB, and when I tried to use one as data and the other one as parity, Unraid told me "Disk in parity slot is not biggest" and array is not permitted to start. I know the topic about "HPA mode", but I'm not using Gigabyte motherboard, my machine is HPE Microserver 10+ and the command hdparm indicates that HPA is disabled for both disks. Any clues for what's going on? Thanks ! tower-diagnostics-20210731-1847.zip

Indeed, parity disk is part of the "array". I tried use one of 5TB HDD disks as the parity, but the parity check will go through the entire 5TB instead of first 2TB or something like that, too slow to take, that's why I'm using them as backup. Now I can confirm that I don't have to go get the NVME SSD, just SATA SSD is enough.

I'm considering what kind of SSD (SATA SSD or NVME SSD) to buy for the parity check, I'm using a 4 drive micro server and my current disks are: 2TB Samsung 860 EVO (SSD) 2TB Curcial MX500 (SSD) 5TB WD Black (HDD) 5TB Seagate Barracuda (HDD) Disk 3 and disk 4 are not in the array but mounted with "unassigned devices plugin" to do the backup every week (disk 3) and every month (disk 4), so the parity disk to buy as the parity disk only works with those two SSDs. So my question is that does the parity check speed depend on the reading speed of the data disks? (I think it should, but not that certain) Will there any difference for the parity check on one SATA SSD vs NVME SSD?