A-22
DuraStor 412R/6320SS/7320SS Installation and User’s Guide
Note:
The controllers communicate with each other using SCSI
initiator IDs 6 and 7 on each of the disk channels. You should
not change these IDs.
Advantages
■
Transparent fail-over and fail-back.
■
Single point of failure is the host system. (There are no single
points of failure when dual host systems are configured with
clustering software.)
■
Upstream fail-over.
Disadvantages
■
Lower performance than the active-active mode.
■
Upstream fail-over requires third-party software.
■
Careful administration is necessary, since all the arrays are
reported twice to the host operating system which must use
third-party file share/file lock software to prevent data
overwrites.
DuraStor IUG - Online.book Page 22 Friday, July 19, 2002 3:06 PM