ZFS Hot-Plugging Enhancements

Solaris 10 10/08 Release: In this release, ZFS more effectively responds to devices that are removed and can now automatically identify devices that are inserted.

• You can replace an existing device with an equivalent device without having to use the zpool replace command.

  The autoreplace property controls automatic device replacement. If set to off, device replacement must be initiated by the administrator by using the zpool replace command. If set to on, any new device that is found in the same physical location as a device that previously belonged to the pool is automatically formatted and replaced. The default behavior is off.

• The storage pool state REMOVED is provided when a device or hot spare has been physically removed while the system was running. A hot spare device is substituted for the removed device, if available.

• If a device is removed and then reinserted, the device is placed online. If a hot spare was activated when the device was reinserted, the hot spare is removed when the online operation completes.

• Automatic detection when devices are removed or inserted is hardware-dependent and might not be supported on all platforms. For example, USB devices are automatically configured upon insertion. However, you might have to use the cfgadm -c configure command to configure a SATA drive.

• Hot spares are checked periodically to ensure that they are online and available.

For more information, see zpool(1M).