You cannot switch (or rename) a metadevice that is currently in use. This includes metadevices used as mounted file systems, as swap, or as active storage for applications or databases. Thus, before using the metarename command, stop all access to the metadevice being renamed. For example, unmount a mounted file system using a metadevice. An application or database must have its own internal method for stopping access.
You cannot switch metadevices in an errored state, or metadevices using a hot spare replacement.
A switch can only take place between metadevices with a direct parent/child relationship. You could not, for example, directly exchange a stripe in a mirror that is a master device with the trans metadevice.
You must use the -f (force) flag when switching members of a trans device.
You cannot switch (or rename) a logging device. The workaround is to either detach the logging device, rename it, then reattach it to the trans device; or detach the logging device and attach another logging device of the desired name.
Only metadevices can be switched. You cannot switch slices or hot spares.