Raid 5 MDADM - Raspberry Pi Forums

i have cheap software raid 5 running 3 usb drives on raspberry pi (all connected usb disk docking station).
number major minor raiddevice state
0 8 1 0 active sync /dev/sda1
3 8 97 1 active sync /dev/sdg1
2 8 81 2 active sync /dev/sdf1


have spare disk copy data onto raid... how do it?

temporarily remove 1 of raid disks (g or f) plug in spare usb disk holds data... (of course dont add raid), copy data spare usb raid , re-add (g or f) raid
thinking of performing following commands:

fail on disk raid: mdadm /dev/md10 -f /dev/sdg1
remove disk: mdadm /dev/md10 -r /dev/sdg1
plug in spare usb disk holds data, , mount it.
copy data on raid
re-attach sdg1 , run mdadm /dev/md10 -a /dev/sdg1

above logic , commands correct?
when re-add sdg array take many hours again resyc?

thanks

can not plug usb stick data in alongside 3 usb sticks in array.

whilst might able remove drive raid set seems bad idea, you'll running array in degraded state no redundancy (any issue , data in raid set gone).

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