This page provides information about:
Mirroring is a way of providing fault tolerance for Madge network adapters running under Novell NetWare (3.12 and above), Windows NT 4, or Windows 2000 and XP. It is an extension of the standard fault recovery mechanisms implemented within the drivers and provides an additional level of fault tolerance.
Mirroring allows a redundant slave adapter to be installed as a standby for a master adapter. In the event of a problem with the master adapter, such as a lobe cable fault, the driver switches immediately to using the slave adapter (referred to here as the 'mirror switch'). The mirror switch is invisible to both the server and any attached clients. After a mirror switch, the master adapter becomes the slave and vice-versa. The server may contain multiple mirrored pairs of adapters.
A mirror switch is initiated:
If the adapter closes (for example, due to a lobe cable fault)
If the adapter fails
Or, if you have configured it to do so (as described in the Advanced Mirroring Configuration section of the detailed Mirroring topic for your operating system), a mirror switch is initiated:
If the adapter beacons for longer than the Ring Beacon timeout value
If the adapter remains a single station for longer than the Single Station timeout value
Additionally, for Novell Netware systems, a mirror switch is initiated:
If the adapter signals a lobe cable fault for longer than the LOBE timeout value
|
You can use MDGLG to find out which is the active adapter in a mirrored pair. For details, see Viewing Driver Status (MDGLOG95.EXE). |
Mirroring is supported by LSS in the following environments:
Novell NetWare 3.12 and above when used with CMDGODI.LAN. (See Mirroring under Novell Netware)
Microsoft Windows NT 4 when used with MDGNDIS4.SYS (the mirroring version of the NDIS 4 miniport driver). (See Mirroring under Windows NT 4)
Microsoft Windows 2000 when used with MDGNDIS5.SYS (the mirroring version of the NDIS 5 miniport driver). (See Mirroring under Windows 2000 and XP)
The following adapters support mirroring:
Smart Mk4 PCI Adapter (part number: 51-05)
Smart Mk4 Low Profile PCI Adapter (part number: 53-05)
RapidFire 3140v2 16/4 TR PCI Adapter (part number: 3140 2010)
RapidFire 3140 Low Profile PCI Adapter (part number: 31-04)
RapidFire 3140 16/4 TR PCI Adapter (part number: 3140)
Smart 100/16/4 PCI-HS Ringnode (part number: 51-07)
Smart 16/4 PCI Ringnode Mk2 (part number: 51-02)
Smart 16/4 PCI Ringnode Mk3 (part number: 51-04)
Mirroring requires a slave adapter to be associated with each master adapter in the computer. You must, therefore, install one slave adapter in a computer for each master adapter which is to be mirrored.
When using mirroring, you must specify a locally-administered node address override (LAA). This is to enable both the master and slave adapters to open with the same node address which is necessary to ensure that clients can still communicate with the server after a mirror switch.
|
Madge recommends that when using adapter mirroring, both adapters are on the same ring. It is also advisable that the master and slave adapters are connected to different hubs to protect against individual hub failure. |
|
If the mirrored adapters are running in DTR mode, Madge recommends that you configure the switch ports to transparent routing mode rather than source-routing mode. |
See Also: