A metadevice, regardless if it is used for a file system, application, or database, can be expanded by adding slices. This includes: striped metadevices, concatenations, and concatenated stripes; mirrors (submirrors); RAID5 devices; and trans metadevices.
In most cases, you can concatenate a metadevice that contains an existing file system while the file system is in use. Then, as long as the file system is UFS, it can be expanded (with the growfs(1M) command) to fill the larger space without interrupting access to the data.
Once a file system is expanded, it cannot be shrunk. This is a limitation of UFS.
Applications and databases using the raw device must have their own method to "grow" the added space so that the application can recognize it. DiskSuite does not provide this capability.
When a slice is added to a RAID5 metadevice, it becomes a concatenation to the device. The new slice does not contain parity information. However, data on the new slice is protected by the overall parity calculation that takes place for the device.
Once a slice is attached to a metadevice, it cannot be removed.
You can expand a logging device by adding additional slices. You do not need to run the growfs(1M) command, as DiskSuite automatically recognizes the additional space on reboot.