Mdadm - Known Problems

Known Problems

A common error when creating RAID devices is that the dmraid-driver has taken control of all the devices that are to be used in the new RAID device. Error-messages like this will occur:

mdadm: Cannot open /dev/sdb1: Device or resource busy

Typically, the solution to this problem involves adding the "nodmraid" kernel parameter to the boot loader config. Another way this error can present itself is if the device mapper has its way with the drives. Issue 'dmsetup table' see if the drive in question is listed. 'dmsetup remove ' will remove the drive from device mapper and the "Device or resource busy" error will go away as well.