Dynamic Reconfiguration User's Guide 2.5.1

2.1.2.2 DR Detach

To detach a device, these strict conditions must be satisfied.

1. The device must not be in use or opened by any user or system process.
2. The device driver must support the DR interface (DR safe driver), to remove the device instance.

It is not always possible to meet the first condition. For example, it is not possible to umount the root file system or any other file system that is vital to the user. To solve this problem, the administrator can use the I/O Multipathing feature to set up alternate paths to the crucial devices, or use other disk mirroring software to mirror the crucial file systems.

To work around non DR safe drivers, the administrator must stop all usage of the devices controlled by the driver and then unload the driver using modunload(1M).

Please refer to section 2.2 "DR Device Driver Requirement" about DR safe driver.