For host systems that are not DMP capable, having two paths from the same host machine to the same drive can cause problems. For example, if the two channels are connected to the same host machine when running an operating system that does not support DMP, two separate disks will be reported by the operating system even though both reported disks are the same physical storage. This can cause corruption to occur if the drive is subsequently accessed down both channels. See Single Channel Mode for Early Revision Drives on page 66.
DRIVE CONFIGURATION
To accommodate both DMP and non-DMP capable systems, the SSD can be configured so that it only operates (and is only visible) down one of the two channels. This feature is most likely to be used on systems that do not support DMP but where the drives in the same JBOD chassis are to be mirrored. Enabling just the A channel for the main drive and the B channel on the mirror drive will cause both drives to be visible via separate host channels, thereby preventing any single point of failure.
The feature is enabled by inserting a 2mm option jumper onto the two pins marked as JP1 on the underside of the drive. Please note that jumper JP1 is located on the 10-way right-angled connector that also serves as a test connector during manufacture. The drive will require power cycling after JP1 is installed or removed. When this feature is enabled, the LSB of the SELECT_ID determines the port that the drive will use. If the SELECT_ID is even, then port A is used. If the SELECT_ID is odd, then port B is used.
WARNING: Only insert a jumper across the pins clearly labeled as JP1 on the PCB silk-screen. If JP1 is not marked, then please read the following for information regarding early revision drives.
FAULT SIGNALS
Under certain conditions, the SSD will drive the Fault LED Out (fault signal) on the SCA-2 interface. In most system configurations, this will normally be connected to an LED on the chassis that is visible to the user.
ZeusIOPS 3.5-Inch Fibre Channel Solid State Drive Product Manual Rev. 1.0 | 63 |
