Fujitsu DX440 S2 Computer Drive User Manual


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Chapter 8 Advanced Copy Management
8.2 Functions in the Action Area for Advanced Copy
ETERNUS Web GUI User’s Guide
Copyright 2013 FUJITSU LIMITED P2X0-1090-10ENZ0
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How to calculate the copy table size
A dedicated memory area is required for Advanced Copy management and is allocated as a table size. The
table size and resolution settings are determined by the copy capacity and the number of sessions (volumes)
that will be run simultaneously.
S1: Refers to the table size (MB) for EC/REC and for OPC/QuickOPC/SnapOPC/SnapOPC+ without OPC
Restoration.
S2: Refers to the table size (MB) for OPC/QuickOPC/SnapOPC/SnapOPC+ with OPC Restoration.
(Table size (S)) [MB] = (S1) + (S2)
Round the derived value up to the next multiple of 8 to obtain the correct setting for the copy table size.
A copy table of the appropriate size (as derived above) is created in each CM.
If the total table size value (S) exceeds the maximum size allowed, adjust the resolution (M) upward
until the maximum table size is no longer exceeded. The resolution (M) should be as small as possible.
Maximum allowed table sizes are as follows:
Allowance should be made for possible increases in the copy capacity.
If the resolution is changed during an existing copy session, the table sizing formula described in this
section is not applied.
The same bitmap ratio (M) value must be used by both the copy source and copy destination storage sys-
tems. If the bitmap ratio settings for the copy source and copy destination storage systems are different,
REC cannot be performed. Note that the table sizes (S) do not need to be identical. If different
recommended resolutions are calculated for the copy source and copy destination storage systems, use
whichever resolution is greater for both storage systems. If the resolution (M) is changed, recalculate the
table size (S) setting for the storage system with the new resolution.
The calculated parameters are "Resolution (M)" and "Table Size (S)". It is assumed that almost 100% of the
copy table size is used.
Storage system name Maximum copy table size (per CM)
ETERNUS DX80 S2 256MB
ETERNUS DX90 S2 256MB
ETERNUS DX410 S2 512MB
ETERNUS DX440 S2 4096MB
ETERNUS DX8100 S2 1024MB
ETERNUS DX8700 S2 12288MB