Fujitsu Eternus DX90 S2 - Page 103

These copy methods all provide access to the data as it exists at a specific point in time, but there are different features, advantages
and disadvantages to each method as detailed below:
Function Name
Copy Type
Snapshot Copy Clone Copy
SnapOPC+ EC OPC QuickOPC
Copy method Copy-on-write
method
Mirror breaking
method
Background copy
method
Background copy
method
Timing of actual copy
load
- Before "mirror
breaking"
After the copy
command is issued
After the copy
command is issued
Effect on access to
the copy source while
copy is running
Yes None Minor Minor
Effect on access to
the copy source after
copy has "finished"
Yes None Slight during
background copy
Slight during
background copy
Lifetime of copy
session
Until session is
stopped
Until the Equivalent
state is stopped
Until background
copy is completed
Until session is
stopped and copy is
completed
Size of copy
destination area
Sufficient for
changed areas
(Snapshot)
Same as the copy
source
(Clone)
Same as the copy
source
(Clone)
Same as the copy
source
(Clone)
Copy action during
restore
Copy back only the
already copied data
For ETERNUS DX60/
DX60 S2/DX80/DX90,
restore operation is
not available (use OS
tools to copy whole
files instead)
- Copy back all the
data by OPC
- EC Reverse
(Suspend ->
Reverse ->
Resume) only
copies updated
areas
- If OPC is active,
copy back only
the already
copied data
(Restore OPC)
- If OPC is
completed, copy
back all of the
copied data
Copy back only the
already copied data
Best used for... - Temporary
backup area for
backup to tape
- Backup to disk
for file server and
- Backup to disk
- Creation of
testing data
- Backup to disk
- Creation of
testing data
- Backup to disk
- Creation of
testing data
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