Can someone explain the md disk setup?

[jbeez]

I have a new truenas scale install, its about a month old. I have 6 18TB seagate exos drives. One of the drives is bad, not a big deal I'm getting it taken care of. They're in a raidz2, this is on a Dell r730xd using the mini HBA 330 daughterboard.

I noticed this in the log files, and I'm not sure why its referencing raid1 md?

Jun 11 10:53:52 nas kernel: md/raid1:md127: not clean -- starting background reconstruction
Jun 11 10:53:52 nas kernel: md/raid1:md127: active with 3 out of 3 mirrors
Jun 11 10:53:52 nas kernel: md127: detected capacity change from 0 to 4190080
Jun 11 10:53:52 nas kernel: md: resync of RAID array md127
Jun 11 10:53:53 nas kernel: Adding 2095036k swap on /dev/mapper/md127. Priority:-5 extents:1 across:2095036k FS
Jun 11 10:54:02 nas kernel: md: md127: resync done.

Also running NetData and it shows this:

Fedex should be bringing another disk today and I can replace it but, this is mostly just a curiosity for me. When I ran raw FreeBSD for my nas I didn't do anything with MD.

Thanks,

 

[Patrick M. Hausen]

TrueNAS is automatically creating mirrored swap devices on startup using md. There's nothing to worry about.

 

[neofusion]

On a positive side, you now have a spare on hand.