Proware EP-3164D-GAS3, User Manual

Page: 123 / 160

iSCSI GbE to SAS/SATA II RAID Subsystem
User Manual 123
3. Lockdown: Dual controller mode. The firmware of two controllers is different or the
size of memory of two controllers is different. In this stage, only master controller
can work and I/O will force to write through for protecting data.
4.
Single: Single controller mode. In the stage, the controller must stay in slot A.
Dongle boards for SATA drives are not necessary. The differences between single
and degraded are described on the following. There is no error message for inserted
one controller only. I/O will not force to write through. And there is no ownership of
RG. Single controller mode can be upgraded to dual controller mode, please contact
the distributor for upgradable.
In addition, iSNS server is recommended. It’s important for keeping I/O running
smoothly when RG ownership is switching or single controller is failed. Without iSNS
server, when controller 1 fails, the running I/O from host to controller 1 may fail because
the time which host switches to the new portal is slower than I/O time out. With iSNS
server, this case would not happen.
NOTE: iSNS server is recommended for dual controller system.