Shared Memory - Hitachi G1500 Hardware Manual

Total logical capacity of external volumes
+ internal volumes per CLPR
100,000 GB or more
128,000 GB or more
182,000 GB or more
218,000 GB or more
254,000 GB or more
290,000 GB or more
326,000 GB or more

Shared memory

Shared memory holds storage system configuration information and it resides in the
cache. The capacity of the shared memory + the capacity of the cache memory = the
total capacity of the cache memory needed by the storage system.
The capacity overheads 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.
SI/ HDP/
Number of
VM/
control
unit NDM
1-64 (16k Apply Appl
LDEV) y
1-64 (16k Apply Appl
LDEV) y
Hitachi Virtual Storage Platform G1000, G1500, and VSP F1500 Hardware Guide
Determining factor of SM capacity
1
Software
TC/
TI/ UR/ HDT/
FC TPF GAD AF
— — —
— Appl —
y
Chapter 2: Storage system hardware overview
Recommended data cache capacity per
30 GB or more
32 GB or more
40 GB or more
48 GB or more
56 GB or more
64 GB or more
72 GB or more
HDP/
HDT/
AF
extension
64KL
DEV
exten
sion 1 2 3
— — — —
— — — —
Shared memory
CLPR
SM
iSC capacit
SI DC y
— — 16 GB
— — 24 GB
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