Installation manual

Caching
For 80 percent of the configurations, enable both read and write cache. Assign as much as
possible to write cache. Split the remaining memory between SP A read cache and SP B read
cache. Ensure that read and write cache is enabled for each LUN.
Cache settings and other SP information
Table 6 describes the user-defined and default storage system properties.
Table 6. Cache settings and SP information
Properties Set Default setting Notes
General Tab
Name See note CXtype_ipSPA_ipSPB Use Customer Naming rules
Statistics Logging Box checked Box not checked
Cache Tab
Page Size Default 8 KB
Low Watermark Default 60
High Watermark Default 80
Enable Watermarks Default Box checked
SP A Read Cache Box checked Box not checked
SP B Read Cache Box checked Box not checked
Write Cache Box checked Box not checked
HA Cache Vault Default Box checked
Memory Tab
SP A/SP B Read Cache See Note 0 Leftover memory from write cache
should be split between SP A and
SP B read cache.
Write Cache As much as
allowed
0 Depends on Dell/EMC CX Series
model
RAID 3 Memory Do not use 0
Storage Access Tab
Access Control Enabled Box checked Box not checked
Software Tab
Commit See note This button pertains to upgrades.
This button is grayed out if commit
has already been done.
Revert See note This button pertains to upgrades.
This is grayed out if commit
already done.
Software online upgrades
EMC recommends Host Agents be upgraded as soon as possible so they are the same revision
as the Navisphere revision on the storage system. The management station must be running the
same revision as the highest revision of Navisphere running in the domain. Navisphere software
is backwards-compatible, so the management station may be upgraded before the storage
systems are upgraded.
Upgrades to the storage system can be achieved by an operation called online upgrade. Online
upgrades require that no more than 100 I/Os are running on the first five disks in the storage
system. EMC recommends that all online upgrades be performed at off-peak hours.
Dell/EMC CX Series Initial Configuration
Best Practices Planning 18