Hitachi G1500 - Shared Memory

Total logical capacity of external volumes
+ internal volumes per CLPR
Recommended data cache capacity per
CLPR
100,000 GB or more 30 GB or more
128,000 GB or more 32 GB or more
182,000 GB or more 40 GB or more
218,000 GB or more 48 GB or more
254,000 GB or more 56 GB or more
290,000 GB or more 64 GB or more
326,000 GB or more 72 GB or more
Shared memory
Shared memory holds storage system conguration information and it resides in the
cache. The capacity of the shar
ed memory + the capacity of the cache memory = the
total capacity of the cache memory needed b
y the stor
age system.
The capacity o
verheads associated with the capacity saving function (data deduction)
include capacity consumed by metadata and capacity consumed by garbage (invalid)
data. For more information, see the Provisioning Guide for Open Systems. The
recommendation is to use 0.2% of active data size as cache size (200 GB of cache for
every 100 TB of pool capacity to be reduced).
The following table shows the shared memory capacity needed depending on the kind of
software applications installed in the system.
Number of
control
unit
Determining factor of SM capacity
iSC
SI DC
SM
capacit
y
Software
1
64KL
DEV
exten
sion
HDP/
HDT/
AF
extension
SI/
VM/
NDM
HDP/
TI/
FC TPF
TC/
UR/
GAD
HDT/
AF 1 2 3
1-64 (16k
LDEV)
Apply Appl
y
— — — — — — — — — 16 GB
1-64 (16k
LDEV)
Apply Appl
y
— Appl
y
— — — — — — — 24 GB
Shared memory
Chapter 2: Storage system hardware overview
Hitachi Virtual Storage Platform G1000, G1500, and VSP F1500 Hardware Guide 54