IBM DS3500 - Page 229

Chapter 8. Administration - Subsystem Management 205
Draft Document for Review March 28, 2011 12:24 pm 7914Admin_Subsystem.fm
Figure 8-14 Change subsystem menu
Battery Settings
The DS3500 storage subsystem batteries do not maintain expiration dates. Battery can be
replaced only when the LEDs indicates that they are failed, or Recovery Guru recommends to
do it. The battery is periodically checked by DS3500 controller firmware after every eight
weeks. You have only an option (see Figure 8-15) to set the time and day of week when the
check (learn cycle) will start.
Select Storage Subsystem  Change  Battery Settings to set the scheduled day and
time for battery check.
Figure 8-15 Battery Settings
Cache Settings
This menu item sets global cache settings of DS3500 storage subsystem. It is possible to set
other cache setting as dedicated for each Logical Drive. It is described in 9.5.2, “Change
Cache Settings” on page 247. Recommended cache settings are depending on required host
load and type of load and can vary. Best practices for cache settings are described in 3.3.10,
“Cache parameters” on page 69.
Select Storage Subsystem  Change  Cache Settings and window as in Figure 8-16 on
page 206 opens.
Learn Cycle: The learn cycle for the DS3500 is much shorter than previous DS3000
models and takes about 15 minutes to complete. During this period the write caching on all
of the logical drives may be disabled if battery low threshold is reached. For best practice,
we recommend to schedule the learn cycle during low usage period on the storage
subsystem.