Hitachi 9900 Series Indoor Furnishings User Manual


 
Dual data paths and dual control paths connecting every component.
Mirrored cache for all write data instead of single image cache.
3
GDPS support.
Hitachi TrueCopy combined with ShadowImage
for disaster recovery.
•Hitachi NanoCopy
to provide Point-in-Time copies without requiring
quiescence of databases or applications.
High-availability, custom designed disk drives.
“Phone home” capability to notify the Hitachi support center quickly of any
incident that may affect availability.
Open Systems High-Availability Middleware Support
Open systems server vendors and third-party software vendors such as VERITAS
®
software have developed a class of software known as “high-availability middleware” to
help reduce downtime by automatically detecting faults and recovering data services on a
redundant set of hardware. Without high-availability middleware, time is lost while a fault
goes undetected. Once the fault is detected, a diagnose/repair/replace action must take
place before data-service recovery can begin. High-availability middleware can begin an
automated recovery process immediately on the redundant hardware. The recovery process
without high-availability middleware involves time-consuming and error-prone manual
operations, which may include resetting the SCSI bus, restarting drivers, reassigning IP
addresses, recovering and restarting applications and transactions, and even rebooting.
Hitachi is the only major
supplier of enterprise
class storage systems with
a 100% availability
guarantee.
Figure 21 - The
Lightning 9900
offers a
far more complete range
of availability protection
than competitive
products.
The recovery process
without high-availability
middleware involves
time-consuming and
error-prone manual
operations.
Hitachi Data Systems
26
3
Some competitive products do not have dual cache like the Hitachi Lightning 9900
. If there
is an unrecoverable error in cache, there is no duplicate backup copy. With these products
there is an increased risk of lost data, especially if the loss occurs in the hardware status
area. The Lightning 9900
, of course, can never have this problem since all status areas and
write data are duplexed.